TJ 


UC-NRLF 


315    mi 


RICHARDS' 


A  C  O  N 


<r 

REESE    LIBRARY 

OF   TBB 

UNIVERSITY   OF   CALIFORNIA., 

Received  J_  *r^5fc# &&/,  7<?f  ^ 

Accession?  No.  .^(f^l-vb        Shelf  No. ... 


A   TREATISE 


R  I  C  H  A  K  D  S 

STEAM-ENGINE  INDICATOR 


DIRECTIONS  FOE  ITS  USE. 


BY    CHARLES    T.    PORTER. 


REVISED, 

WITH  NOTES  AND  LARGE  ADDITIONS   AS  DEVELOPED  BY  AMERICAN 

PRACTICE  ;   WITH  A  SUPPLEMENT,    DESCRIBING  THE  LATEST 

IMPROVEMENTS  IN   THE  INSTRUMENTS  FOR  TAKING, 

MEASURING,   AND   COMPUTING  DIAGRAMS. 

ALSO,  AN  APPENDIX, 
CONTAINING   USEFUL   FORMULAS   AND  RULES   FOR  ENGINEERS. 


BY  F.   W.   BACON,    M.E., 

OF  THE  AMERICAN  SOCIETY   OF  CIVIL  ENGINEERS. 


OUKTH    EDITION. 


NEW   YORK  : 

D.      VAN       NOSTRAND, 
33  MURRAY  STREET. 

1883. 


Copyright,  1873,  £y  Z>.  F«»  Nostrand. 


Copyright,  1880,  ^  Z>.  Fa»  Nostrand, 


PREFACE. 


IN  introducing  the  Richards  Improved  Steam- 
Engine  Indicator,  we  desire  to  call  the  attention  of 
the  numerous  class  who,  as  constructors,  managers 
or  owners,  are  interested  in  the  steam-engine,  to 
the  advantages  which  it  possesses.  In  the  follow- 
ing pages  all  necessary  information  is  furnished 
concerning  the  instrument  and  its  application,  and 
such  instruction  is  given  to  those  who  are  not  al- 
ready skilled  in  the  use  of  the  Indicator,  as  will  en- 
able them  to  employ  it  to  the  best  advantage. 

The  Indicator  was  invented  by  Watt.  For  some 
time  it  was  kept  by  him  a  secret,  but  became  known 
before  his  death,  and  to  its  use,  now  quite  general, 
we  are  more  indebted  than  to  anything  else,  for 
the  degree  of  excellence  which  the  steam-engine 
has  attained.  The  employment  of  more  rapid 
velocities  of  piston,  with  higher  pressures  of  steam, 
and  higher  grades  of  expansion,  which  has  become 
so  extensive  and  promises  ultimately  to  be  uni-- 
versal,  has  increased  greatly  the  importance  of  the 
Indicator  ;  since  this  is  the  only  means  as  yet 
known,  by  which  the  engineer  can  render  himself 


4:  PREFACE. 

familiar  with  the  action  of  steam  under  these  new 
conditions.  Unfortunately,  every  form  of  this  in- 
strument has  hitherto  failed  in  its  application  to 
engines  of  this  class.  The  long  and  tremulous 
spring  used  in  them  was  put  in  a  state  of  violent 
oscillation  by  the  momentum  of  the  piston  and 
attached  parts,  and  the  result  was  a  serrated 
figure,  from  which  but  little  information  could  be 
extracted ;  so  that,  after  a  time,  attempts  to 
employ  the  Indicator  in  this  important  and 
rapidly  enlarging  field  were  qiiite  abandoned. 

Under  these  circumstances,  the  appearance  at 
the  Great  Exhibition  of  1862  of  the  improved  form  of 
this  instrument,  invented  by  Mr.  Charles  B.  Richards, 
an  engineer  of  Hartford,  Connecticut,  U.  S.,  may 
not  improperly  be  regarded  as  an  event  of  some 
importance.  The  action  of  this  Indicator  was 
found  to  be  quite  perfect,  under  the  severest  tests 
to  which  it  could  there  be  subjected,  and  recently 
it  has  been  still  more  thoroughly  tried,  on  an 
express  engine  on  the  London  and  South-Western 
Railway,  and  its  performance  has  more  than  real- 
ized the  expectations  formed  of  it.  Two  instru- 
ments, among  the  first  manufactured  by  us,  were 
employed,  with  which  nearly  two  hundred  dia- 
grams were  taken,  on  a  trip  to  Southampton  and 
back,  at  pressures  varying  from  80  Ibs.  to  130  Ibs., 
at  rates  of  motion  varying  from  the  slowest  up  to 
260  revolutions  per  minute,  giving  a  speed  of  55 
miles  per  hour,  and  at  all  points  of  cut-off ;  and 


PREFACE.  5 

they  were  found  uniformly  to  work  with  the  same 
steadiness  at  the  highest  velocity  as  at  the  lowest, 
and  at  the  earliest  point  of  cut-off  as  at  the  latest. 
Copies  of  a  few  of  the  diagrams  are  here  given. 

We  do  not  claim  for  these  Indicators  superiority 
on  engines  running  at  high  velocities  only,  though 
certainly  it  is  there  most  apparent  where  others 
will  not  answer  at  all ;  but  we  believe  also,  for 
reasons  herein  explained,  that  they  will  be  found 
in  practice  to  be  the  only  correct  Indicators  for  en- 
gines running  at  any  speed,  even  the  lowest. 

We  have  only  to  add,  that  no  pains  have  been 
spared  to  attain,  in  the  manufacture  of  these  instru- 
ments, the  highest  degree  of  accuracy  and  excel- 
lence, and  that  if  the  directions  here  given  are 
attended  to,  their  indications  may  be  implicitly  re- 
lied on. 

ELLIOTT  BROTHERS. 


PREFACE. 


THE  demand  for  an  elementary  treatise  <on  the 
Richards  Steam-Engine  Indicator,  together  with 
the  solicitation  of  professional  friends,  has  induced 
me  to  undertake  the  preparation  of  the  work. 

The  original  and  very  excellent  work  of  Mr.  Por- 
ter, now  out  of  print,  being  principally  an  illustra- 
tion of  English  engines  and  English  practice,  leaves 
room  for  a  work  combining  American  engines  and 
American  practice. 

I  have  therefore  used  much  of  Mr.  Porter's,  and 
added  new  matter  and  new  diagrams — the  result 
of  a  large  experience,  extending  over  six  years. 

The  new  diagrams  introduced  were,  with  one  or 
two  exceptions,  taken  by  myself. 

The  diagrams  taken  November  14th,  1867,  from 
the  locomotive  No.  50,  built  by  the  "  Taunton  Lo- 
comotive Works,  "  are  believed  to  be  the  first  ever 
taken  in  this  country  from  a  locomotive  when  mak- 
ing a  regular  trip  with  an  express  train. 

It  will  be  of  interest  to  the  American  engineer 
to  compare  them  with  those  from  an  English  loco- 
motive, as  shown  in  the  work. 


8 

In  order  to  make  the  work  more  useful  to  the 
practical  engineer,  an  Appendix  has  been  added, 
containing  various  formulas,  which,  during  an  ex- 
perience of  more  than  thirty  years  as  a  practical 
engineer,  have  been  collected,  but    never  before 
given  to  the  public.     The  new  rule  to  measure  and 
compute  diagrams  (page  42),  will  be  found  a  very 
expeditious  and   correct   mode.     The   liabilities  to 
error  being  reduced  as  ten  to  one.    It  was  brought 
to  my  notice  by  Mr.  Chas.  E.  Emery,  engineer,  New 
York  City.    It  is  now  for  the  first  time  published, 
so  far  as  I  know. 

The  prime  object  has  been  to  give  nothing  that 
is  not  known  by  practical  experience  to  be  correct, 
also  to  give  it  in  a  way  that  will  be  understood  by 
any  one  capable  of  filling  the  place  of  an  engineer. 

F.  W.  BACON. 

BOSTON,  October,  1873. 


PREFACE  TO  THIRD  EDITION. 


A  THIRD  edition  of  this  work  is  called  for, 
-*-\*  showing  that  the  Indicator  is  now  being- 
appreciated.  Engineers  are  becoming  educated  in 
its  use  ;  it  reveals  to  them  many  things  which  they 
thought  they  knew,  but  find  they  didn't ;  it  has  got 
the  attention  of  engine  constructors  ;  it  has  inspired 
the  genius  of  the  inventor  and  designer  ;  the  speed 
of  the  engine  is  increased,  the  immense  ponderous 
mass  of  matter  formerly  set  in  motion  is  largely  re- 
duced, space  is  economized,  compounding  is  shown 
to  be  a  success  and  a  necessity,  coal  and  water  bills 
are  being  reduced  to  a  minimum. 

All  these  desirable  things,  it  is  safe  to  say,  the 
teachings  of  the  Indicator  has  not  only  rendered 
possible,  but  has  accomplished  de  facto. 

Still  there  is  a  wide  margin  yet  to  fill  before  its 
office  is  accomplished. 

Increasing  the  speed  of  the  engine  rendered  an 
improvement  necessary  in  the  Indicator,  which  our 


x  PREFACE:  TO  THIRD  EDITION. 

Supplement  shows  to  have  been  admirably  accom- 
plished by  Mr.  Thompson. 

The  measurement  and  computation  of  diagrams 
heretofore  was  a  long,  tedious,  and  unsatisfactory 
work  ;  now  the  Planimeter  has  been  produced,  at  a 
price  that  can  be  reached  by  all,  it  has  reduced  the 
time  and  labor  to  a  few  minutes,  with  the  greatest 
accuracy. 

F.  W.  BACON,  M.  K, 

No.  8  PEMBERTON  SQUABE,  BOSTON. 


RICHARDS 


IMFKOVED 


STEAM-ENGINE    INDICATOR. 


THE  NATURE  AND  USE  OF  THE  INDICATOR. 

THE  Steam-Engine  Indicator  is  an  instrument 
designed  to  show  the  pressure  of  steam  in  the 
cylinder,  at  each  point  of  the  piston's  stroke.  It 
does  this  in  the  following  manner :  A  pencil, 
moving  up  and  down  with  the  varying  pressure  of 
the  steam,  draws  a  line  on  paper,  which  has  a 
motion  backward  and  forward,  coincident  with 
that  of  the  piston.  The  paper  is  placed  on  a 
drum,  which,  while  the  piston  is  advancing,  is 
caused  to  make  about  three-quarters  of  a  revolu- 
tion, by  means  of  a  cord  connected  with  a  suitable 
part  of  the  engine,  and  while  the  piston  is  rece- 
ding, is  brought  back  to  its  first  position  by  the 
reaction  of  a  spring.  The  pencil  is  attached  to  a 
small  piston,  moving  without  friction  in  a  cylinder, 
1* 


10  RICHARDS'    STEAM-ENGINE   INDICATOR. 

and  the  motion  of  which  is  resisted  by  a  spring  of 
known  elastic  force. 

TLe  pressure  of  the  atmosphere  is  always  on 
the  upper  side  of  this  piston,  and  when  the  com- 
munication with  the  cylinder  of  the  engine  is 
closed,  it  is  on  the  under  side  also ;  and  if  then 
the  motionless  pencil  be  applied  to  the  moving 
paper,  it  will  draw  a  line  which  is  called  the 
atmospheric  line.  When  the  commiTjiicatioii  is 
opened  between  the  under  side  of  this  piston  and 
one  end  of  the  cylinder  of  the  engine,  the  piston 
will  be  forced  upward  by  the  pressure  of  the 
steam,  or  downward  by  that  of  the  atmosphere, 
as  the  one  or  the  other  preponderates ;  and  if 
now  the  pencil  be  applied  to  the  moving  paper,  it 
will  describe,  during  one  revolution  of  the  engine, 
a  figure,  each  point  in  the  outline  of  which  will 
show,  by  its  distance  above  or  below  the  atmos- 
pheric line,  the  pressure  in  that  end  of  the  cylin- 
der, when  the  piston  was  at  the  corresponding 
point  of  its  forward  or  return  stroke.  The  spring 
which  resists  the  motion  of  the  Indicator  piston 
is  so  proportioned  in  strength  that  a  change  of 
pressure  of  one  pound  on  the  square  inch  shall 
cause  the  pencil  to  move  up  or  down  a  certain 
fractional  part  of  an  inch. 

The  diagram  thus  described  shows  on  inspection 
tho  following  particulars,  viz.,  what  proportion  of 
the  boiler-pressure  is  obtained  in  the  cylinder  ; 
how  early  in  the  stroke  the  highest  pressure  ia 


RICHARDS'  STEAM-ENGINE  INDICATOR.  11 

reached  ;  how  well  it  is  maintained  ;  at  what  point, 
and  at  what  pressure,  the  steam  is  cut  off ;  whether 
it  is  cut  off  sharply,  or  in  what  degree  it  is  wire- 
drawn ;  at  what  point,  and  at  what  pressure  it  is 
released ;  in  a  non-condensing  engine,  whether  it 
is  freely  discharged,  or  what  proportion  of  it  re- 
mains to  exert  a  counter-pressure ;  in  a  condens- 
ing engine,  the  amount  of  the  vacuum,  and  how 
quickly,  or  how  gradually  it  is  obtained  ;  and  in 
both  classes  of  engines,  whether,  before  the  com- 
mencement of  the  stroke,  there  is  any  compression 
of  the  vapor  remaining  in  the  cylinder,  and  if  so, 
at  what  point  it  commences,  and  to  how  high  a 
pressure  it  rises.  From  the  diagram,  the  mean 
pressure  exerted  during  the  stroke,  to  produce  and 
to  resist  the  motion  of  the  piston,  may  be  ascer- 
tained, and  thus  the  engineer  may  come  to  l^now 
accurately  the  amount  of  power  required  to  over- 
come the  whole  aggregate  resistance  on  the  engine, 
and  also,  by  taking  separate  diagrams  for  each,  the 
power  required  by  each  of  the  several  resistances 
or  classes  of  resistance  separately.*  He  may  en- 

*  This  we  find  of  great  use  when  called  to  determine  (as 
we  often  are)  the  power  used  by  tenants.  The  landlord  lets 
power  to  his  tenants  ;  it  is  fixed  at  a  given  price  per  horse- 
power. The  question  arises,  how  much  the  tenant  does  use. 
This  is  accurately  determined.  The  practice  is  this:  We  take 
several  diagrams,  one  from  each  end  of  the  cylinder,  when 
the  engine  is  doing  all  the  work,  noting  the  number  of  revo- 
lutions being  made  when  each  pair  is  taken.  Should  there 


12  RICHARDS'  STEAM-ENGINE  INDICATOR. 

deavor  also  to  ascertain  the  causes  of  the  various 
features  presented  in  the  diagram,  and  thus  to 
learn  the  effect  produced  by  this  or  that  form  or 
arrangement  of  parts,  and  to  detect  any  imperfec- 
tion in  their  construction  or  action. 

It  must  be  borne  in  mind,  that  the  Indicator 
shows  only  the  pressure  at  each  point  of  the 
stroke;  to  represent  this  faithfully  is  its  sole  office. 
It  tells  nothing  about  the  causes  which  have  de- 
termined the  form  of  the  figure  which  it  describes. 
The  engineer  concludes  what  these  are,  as  the 
result  of  a  process  of  reasoning,  and  this  is  the 
point  where  errors  are  liable  to  be  committed. 

be  a  difference  of  speed  of  the  engine  during  the  time  of 
taking  these  diagrams  it  is  noted  on  each  pair,  and  arranged 
when  worked  up. 

These  diagrams  and  the  result  we  mark  "all  on;"  then  we 
stop  tenant  No.  1,  throw  off  the  belt  that  carries  his  work, 
take  say  three  pairs  of  diagrams,  and  work  them  up.  Now,  as 
much  as  these  are  less  than  the  average  of  those  taken  with 
"all  on,"  so  much  we  charge  tenant  No.  1.  We  then  put  his 
belt  on  and  proceed  with  tenant  No.  2,  and  charge  him  in  the 
same  manner.  Thus  we  proceed  with  all.  In  making  up 
our  accounts  for  each,  and  adding  them,  we  find  the  aggre- 
gate will  fall  short  of  the  gross  of  "all  on."  This  is  as  it 
should  be,  from  the  well-known  fact  that  the  friction  of  the 
engine  and  intervening  machinery  decreases  as  the  power 
required  decreases,  and  vice  versa. 

This  amount  of  decrease  or  increase,  as  the  case  may  be, 
we  have  found  to  vary  from  5  per  cent,  to  8  per  cent,  de- 
pending on  circumstances.  Whatever  it  may  be  it  should  be 
charged  to  the  tenant. 


RICHARDS'  STEAM-ENGINE  INDICATOR.  13 

Conclusions  which  seem  obvious  sometimes  turn 
out  to  have  been  wrong,  and  the  ability  to  form  an 
accurate  judgment,  as  to  the  causes  of  the  pecu- 
liarities presented  in  a  diagram,  is  one  of  the 
highest  attainments  of  an  engineer. 

The  variety  of  diagrams  given  by  different  en- 
gines, and  by  the  same  engine  tinder  different 
circumstances,  is  endless ;  and  there  is  perhaps 
nothing  more  instructive  to  the  student  of  engi- 
neering, as  there  is  nothing  more  interesting  to 
the  accomplished  engineer,  than  their  careful  and 
comprehensive  study,  with  a  knowledge  of  the  mod- 
ifying circumstances  under  which  each  one  was 
taken.  Lines  at  first  meaningless  become  full  of 
meaning;  that  which  scarcely  arrested  his  atten- 
tion, comes  to  possess  an  absorbing  interest;  he 
becomes  acquainted  with  the  innumerable  variety 
of  vicious  forms,  and  learns  the  points  and  degrees, 
as  well  as  the  causes,  of  their  departure  from  the 
single  perfect  form;  he  becomes  familiar  with  the 
effects  produced  by  different  constructions  and 
movements  of  parts,  and  competent  to  judge  cor- 
rectly as  to  the  performance  of  engines,  and  to 
advise  concerning  changes,  by  which  it  may  be 
improved;  he  ceases  to  be  a  mere  imitator  of  ma- 
terial shapes,  and  learns  to  strive  after  the  highest 
excellence,  and,  at  the  same  time,  to  comprehend 
its  conditions.  No  one  at  the  present  day  can 
claim  to  be  a  mechanical  engineer  who  has  not 
become  familiar  with  the  use  of  the  Indicator,  and 


14  RICHARDS'  STEAM-ENGINE  INDICATOR. 

skilful  in  turning  to  practical  advantage  the  varied 
information  which  it  furnishes. 

This  brief  summary  of  the  uses  of  the  Indicator 
would  be  incomplete  without  calling  attention  to 
the  importance  of  applying  it  to  boilers,  as  a  means 
of  testing  the  accuracy  of  the  pressure-gauges,  and 
to  pumps,  for  the  purpose  of  ascertaining  the  causes 
of  any  inefficiency  in  their  action,  and  also  to  the 
condenser  and  the  air  pump  of  condensing  engines. 

The  diagram,  No.  1,  taken  from  one  of  the 
engines  of  a  well-known  steamship,*  is  introduced 
here  to  illustrate  the  action  of  the  Indicator,  as 
just  described. 

The  scale  of  the  Indicator  was  twelve  pounds  to 
the  inch.  The  line  A  B  is  the  atmospheric  line,  and 
c  D  the  line  of  perfect  vacuum.  The  lines  forming 
the  outline  of  the  diagram  will  be  designated,  for 
convenience  of  description,  as  follows : — 

The  line  from  a  to  6,  the  admission-line. 

6  to  c,  the  steam-line. 

"  c  to  d,  the  line  or  curve  of  expansion, 

"  d  to  <?,  the  exhaust-line. 

"  e  to  /,  the  line  of  counter-pressure. 

"  /  to  a,  the  compression-line. 

*  The  engines  from  which  the  diagrams  here  employed  for 
•illustration  were  taken,  will  not  be  mentioned,  except  in  two 
or  three  exceptional  cases ;  the  object  of  this  paper  being,  not 
to  publish  the  comparative  performance  of  different  engines, 
but  to  give  instruction  to  those  who  may  require  it,  in  the  use 
of  the  Indicator. 


RICHARDS'  STEAM-ENGINE  INDICATOR.  15 

The  steam-line  does  not  in  fact  end  at  c,  but  at 
some  unknown  point  beyond  c.  The  diagram  is  divi- 
ded by  lines  drawn  perpendicular  to  the  atmospheric 
line  into  ten  equal  parts,  and  also  by  lines  drawn 
parallel  with  the  atmospheric  line  at  intervals  of 
five  wounds  pressure.  The  object  of  these  is  to 
enable  the  engineer  to  observe  more  accurately  the 
nature  of  the  diagram,  and  to  ascertain  the  mean 
pressure  exerted  during  the  stroke,  the  mode  of 
doing  which  will  be  explained  hereafter.  The  line 
<?  g  is  the  theoretical  expansion  curve  drawn  from 
the  point  c. 

.  From  an  examination  of  this  diagram,  we  con- 
clude that  the  exhaust-port  was  covered  at  the  point 
/,  of  the  return  stroke,  and  the  vapor  remaining  in 
the  cylinder  was  then  compressed  by  the  advance 
of  the  piston  to  a  density,  at  the  commencement  of 
the  forward  stroke,  of  about  five  pounds  above  the 
atmosphere.  The  port  was  then  opened  for  admis- 
sion, and  the  pressure  instantly  rose  to  fourteen 
and  a  half  pounds  above  the  atmosphere.  The 
port  being  opened  wider  and  wider,  this  pressure 
was  maintained  behind  the  advancing  piston  to  the 
point  c,  at  which  it  began  to  fall,  at  first  very 
slowly,  from  the  gradual  closing  of  the  port  by  the 
cut-off  valve.  The  point  at  which  the  port  was 
covered  cannot  be  identified.  It  was  certainly,  how- 
ever, far  beyond  the  point  c,  and  strictly  the  steam  - 
line  continues  to  the  point  of  cut-off,  however  the 
pressure  may  fall  before  that  point  is  reached.  At 


16  RICHARDS'  STEAM-ENGINE,  INDICATOR. 

the  point  d,  the  pressure  had  fallen  by  expansion  to 
two  pounds  above  the  atmosphere.  Here  the  valve 
began  to  open  communication  with  the  condenser, 
and  before  the  piston  commenced  its  return  stroke 
the  pressure  on  this  side  of  it  fell  to  nearly  ten 
pounds  below  the  atmosphere,  and  almost  imme- 
diately after  a  vacuum  of  twelve  pounds  was  formed ; 
and  when  the  return  stroke  was  two-thirds  accom- 
plished, the  counter-pressure  suddenly  fell  half  a 
pound  lower,  and  this  vacuum  was  maintained 
until  the  exhaust-port  was  closed  at  the  point  /. 
We  shall  refer  to  this  diagram  again,  when  on  the 
subjects  of  calculating  the  power  of  the  engine  from 
the  diagram,  and  of  working  steam  expansively. 


OF  TEUTH  IN  THE  DIAGBA.M. 

It  is,  of  course,  of  the  first  importance  that  the 
diagram  given  by  the  Indicator  shall  be  true. 
Causes  of  error  appear  at  every  point,  and  the  de- 
gree of  falsity  arising  from  them  increases  greatly 
with  an  increase  in  the  rate  of  revolution  of  tho 
engine.  It  is  not  possible  to  be  too  critical  in  using 
the  Indicator,  especially  at  high  speeds;  the  errors 
we  are  not  conscious  of  are  the  ones  sure  to  mis- 
lead us. 

The  Conditions  of  a  correct  Diagram  are — 1st, 
that  the  movements  of  the  paper  shall  coincide  ex- 
actly with  those  of  the  piston  ;  and,  2nd,  that  the 


RICHARDS'  STEAM-ENGINE  INDICATOR.  17 

movements  of  the  pencil  shall  simultaneously  and 
precisely  represent  the  changes  of  pressure  in  that 
end  of  the  cylinder  to  which  the  Indicator  is 
attached. 

1st.  Errors  in  the  Motion  of  the  Paper. — The  com- 
mon errors  in  communicating  motion  to  the  paper 
are  of  two  kinds — those  which  arise  out  of  the 
movements  employed,  and  those  which,  when  the 
movements  are  correct,  are  occasioned  by  a  high 
velocity  of  the  parts;  but  with  proper  care  these 
may  all  be  avoided.  We  shall  mention  them  in 
detail  presently,  in  connection  with  instructions  for 
applying  the  Indicator. 

2d.  Errors  in  the  Motion  of  the  Pencil. — These 
are  of  a  more  serious  nature.  The  spring  may  be 
accurate,  but  its  unavoidable  length  and  weakness, 
and  its  weight,  joined  to  that  of  the  piston 
and  other  attached  parts,  and  the  distance  through 
which  these  must  move,  in  order  that  the  indica- 
tions may  be  on  a  scale  of  sufficient  magnitude, 
render  it  impossible  to  obtain  from  engines  which 
run  at  any  considerable  speed,  with  any  form  of 
Indicator  hitherto  in  use,  diagrams  which  can  make 
any  claim  to  accuracy. 

THE  RICHARDS  INDICATOR 

Is  constructed  on  a  plan  by  which  it  is  found  that 
these  difficulties  are  quite  avoided,  and  correct  dia- 


18  RICHARDS'  STEAM-ENGINE  INDICATOR. 

grams  are  obtained  under  all  circumstances.  The 
principal  distinguishing  features  of  this  instrument 
are  a  short  and  strong  spring,  a  short  motion  of 
piston  and  light  reciprocating  parts,  combined  with 
a  considerable  area  of  cylinder,  and  an  arrange- 
ment of  levers  and  a  parallel  motion,  for  multiply- 
ing the  motion  of  the  piston  in  such  a  manner  that 
the  diagram  is  described  in  the  usual  way  and  of 
the  ordinary  size.  The  proportion  between  the 
motion  of  the  piston  and  that  of  the  pencil  is  a 
matter  of  discretion;  that  which  has  been  adopted 
is  1  to  4,  and  the  steadiness  with  which  the  indica- 
tion is  drawn  by  these  instruments,  even  at  the 
highest  speeds  of  piston,  leaves  nothing  to  be  de- 
sired. 

The  diagrams  numbered  2,  3,  4,  5,  are  fair  sam- 
ples of  a  large  number  taken  from  the  locomotive 
"  Eagle,"  on  the  London  and  South- Western  Rail- 
way, in  April,  1863.  In  three  of  them,  the  pencil 
was  held  to  the  paper  during  a  number  of  revolu- 
tions ;  in  diagram  No.  5  it  passed  over  the  paper 
only  once  and  a  half.  They  are  introduced  here  to 
show  the  correct  action  of  the  instrument;  we  shall 
have  occasion  to  consider  them  also  as  illustrations 
of  working  steam  expansively. 

General  Construction  of  the  Indicator. — The  paral- 
lel motion  is  made  as  compact  as  possible.  For 
this  purpose,  a  lever  of  the  third  order  is  employ- 
ed to  multiply  the  motion,  and  the  extremities  of 


KICHABDS"  STEAM-ENGINE   INDICATOR.  19 

the  line  drawn  by  the  pencil  are  permitted  to  have 
a  slight  curvature,  which  considerably  reduces  the 
length  of  the  rods,  and  does  not  affect  the  use- 
fulness of  the  instrument,  the  curvature  at  the 
lower  end  being  below  any  attainable  vacuum, 
while  the  extremity  of  the  scale  above  is  very 
rarely  employed. 

The  Indicators  are  made  of  a  uniform  size;  the 
area  of  the  cylinder  is  one-half  of  a  square  inch, 
its  diameter  being  .7979  of  an  inch.  The  piston  is 
not  fitted  quite  steam-tight,  but  is  permitted  to  leak 
a  little;  this  renders  its  action  more  nearly  friction- 
less,  and  does  not  at  all  affect  the  pressure  on 
either  side  of  it.  The  motion  of  the  piston  is  f  $  of 
an  inch,  and  the  motion  of  the  pencil,  or  extreme 
height  of  the  diagram,  is  3|  inches.  The  paper  cyl- 
inder is  2  inches  in  diameter,  and  the  length  of  the 
diagram  may  be  5  J  inches,  if  this  extent  of  motion 
is  given  to  the  cord.  The  diagram  is  drawn  by  a 
pointed  brass  wire  on  metallic  paper.  This  is  a 
great  improvement  over  the  pencil ;  the  point  lasts 
a  long  time,  cannot  be  broken  off,  and  is  readily 
sharpened,  and  the  diagram  is  indelible.*  The 
steam-passage  has  two  or  three  times  the  area  usu- 

*  We  have  used  the  metallic  pencil  with  thf  prepared  me- 
tallic paper.  It  works  well,  but  the  difficulty  of  procuring  it, 
together  with  its  high  cost,  renders  it  objectionable.  We  use 
heavy,  unsized  paper  with  a  Faber  No.  4  pencil ;  we  succeed 
in  getting  good,  distinct  diagrams,  with  lines  sufficiently  fine 
to  measure  correctly. 


30  EICHABDS'    STEAM-ENGINE   INDICATOR. 

ally  given  to  it.  The  stem  of  the  Indicator  is  coni- 
cal, and  fits  in  a  corresponding  seat  in  the  stop- 
cock, where  it  is  held  by  a  peculiar  coupling,  shown 
in  section  in  the  accompanying  cut  of  the  Indica- 
tor. This  arrangement  permits  the  Indicator  to 
be  turned  round,  so  as  to  stand  in  any  desired  po- 
sition, when,  the  coupling  being  turned  forward, 
the  difference  in  the  pitch  of  the  screws  draws  the 
cone  firmly  into  its  seat;  and  when  the  coupling  is 
turned  backward,  the  cone  is  by  the  same  means 
started  from  its  seat.  The  leading  pulleys  may  be 
turned  by  some  pressure,  to  give  any  desired  direc- 
tion to  the  cord,  and  will  remain  where  they  are 
set.  By  these  means  the  Indicator  can  be  readily 
attached  in  almost  any  situation. 

The  Springs. — In  order  to  adapt  this  Indicator 
for  use  on  engines  of  every  class,  springs  are  made 
for  it  to  4  different  scales,  as  follows  : 

No.  16,  which  is  graduated  16  Ibs.  to  the  inch.      351bs. 

No.  20,          "           "           20  "        "  "       56  " 

No.  30,          "            "  *      30  "        "  "        75   " 

No.  40,          "           "           40  •«        "  "  105  " 

All  the  above  will  also  indicate  15  Ibs.  below  the 
atmospheric  line. 


RICHARDS'   STEAM-ENGINE  INDICATOR.  21 

PEACTICAL    DIRECTIONS    FOB    APPLYING    AND 
TAKING  CARE  OF  THE  INDICATOR 

I.    OF   ATTACHING   THE   INDICATOR. 

When  it  is  practicable,  diagrams  should  be  taken 
from  each  end  of  the  cylinder.  The  assumption 
commonly  made,  that  if  the  valves  are  set  equal,, 
the  diagram  from  one  end  will  be  like  that  from 
the  other,  will  be  shown  by  this  instrument  to  be 
erroneous.  This  is  owing  to  the  difference  in  the 
speed  of  the  piston  at  the  opposite  ends  of  the 
cylinder,  which  is,  at  the  outer  end  of  a  direct- 
acting  engine,  from  one-sixth  to  one-third  greater 
than  at  the  crank  end,  the  difference  varying  ac- 
cording to  the  degree  of  angular  vibration  of  the 
connecting  rod.  In  side-lever,  or  beam-engines,, 
these  proportions  are  reversed,  and  the  speed  of 
the  piston  is  greater  at  the  upper  end  of  the  cylin- 
der. Often,  also,  there  is  a  difference  in  the 
lengths  of  the  thoroughfares,  and  in  the  lead,  or 
the  amount  of  opening,  or  the  point  of  closing  ; 
and  many  times  the  valves  are  supposed  to  be  cor- 
rectly set  when  this  Indicator  will  show  that  they 
are  not.  These,  and  many  other  causes,  will  make 
a  difference  in  the  diagrams  obtained  from  the  op- 
posite sides  of  the  piston. 

Pipes  to  be  avoided. — The  Indicator  should  be 
fixed  close  to  the  cylinder,  especially  on  engines 
working  at  high  speeds.  If  pipes  must  be  usedr 


22  RICHARDS'  STEA.M-EXCUXE  INDICATOR. 

they  should  not  be  smaller  than  half  an  inch  in 
-diameter,  and  five-eighths  in  the  bends,  and  as 
;short  and  direct  as  possible.  Any  engineer  can 
;satisfy  himself  with  this  instrument  that  each  inch 
of  pipe  occasions  a  perceptible  fall  of  pressure 
between  the  engine  and  the  Indicator,  varying  ac- 
cording to  its  size  and  number  of  bends  and  the 
speed  of  the  piston.  Diagrams  have  been  known 
to  show,  from  this  cause  alone,  forty  per  cent,  less 
pressure  than  was  actually  in  the  cylinder. 

Where  to  connect  the  Indicator. — On  vertical  cylin- 
ders, for  tne  upper  end,  the  Indicator-cock  is 
usually  screwed  into  the  cover,  where  the  oil-cup 
is  set,  this  being  removed  for  the  purpose.  For 
the  lowar  end,  it  is  necessary  to  drill  into  the  side 
of  the  cylinder,  at  a  convenient  point  in  £he  space 
between  the  cylinder  bottom  and  the  piston,  when 
on  the  centre,  and  screw  in  a  short  bent  pipe,  with 
A  socket  on  the  end  to  receive  the  Indicator-cock. 
The  Indicator  can  be  used  in  a  horizontal  position ; 
but  it  will  be  found  much  more  convenient  to  put 
in  a  bent  pipe,  and  set  it  vertical.  Sometimes  it 
will  be  necessary  to  drill  in  the  side  of  the  cylinder 
at  the  upper  end  also,  especially  in  double-cylinder 
-engines  having  parallel  motions,  when  the  Indicator 
cannot  generally  be  set  on  the  covers.  Care  must  be 
taken  that  the  piston  does  not  cover  the  hole  when 
on  the  centre.  No  putty  is  necessary  to  make 
these  small  joints,  and  it  should  never  be  used,  as 


RICHARDS   STEAM-ENGINE  INDICATOR.  2£ 

it  is  liable  to  clog  the  instrument.  If  the  screw  fits- 
loosely,  a  few  threads  of  cotton  wound  round  the 
stem  will  prevent  the  escape  of  steam.  Objections 
are  sometimes  made  to  drilling  a  cylinder  or  its; 
heads,  for  the  reason  that  the  borings  as  the  drill- 
passes  through  will  be  left  in  the  cylinder  and 
likely  to  scratch  it;  this,  with  a  little  management,, 
can  be  wholly  prevented,  by  letting  a  little  steam 
on  as  the  drill  enters,  which  will  blow  it  outwards. 

On  horizontal  engines,  the  best  place  for  the 
Indicator  is  on  the  top  or  upper  side,  at  each  end;; 
if  it  cannot  be  placed  there,  bent  pipes  may  be 
screwed  into  the  covers  or  into  the  side  of  the 
cylinder.  In  other  respects  follow  the  directions- 
given  for  vertical  engines.  The  Indicator  should 
never  be  set  to  communicate  with  the  thorough- 
fares. The  current  of  steam  past  the  end  of  the 
pipe  or  the  hole  reduces  the  pressure  in  the  instru- 
ment, and  the  diagram  given  is  utterly  worthless, 
as  any  engineer  can  readily  ascertain  by  making 
the  experiment.  On  oscillating  cylinders  care  must, 
be  taken  to  set  the  instrument  in  such  a  position 
that  the  motion  of  the  cylinder  will  not  have  the 
effect  to  throw  the  pencil  to  and  from  the  paper. 

The  stopcock  being  screwed  firmly  to  its  place, 
screw  the  Indicator  down  to  its  seat,  turning  it  to 
the  most  convenient  position,  and  make  it  fast  by 
turning  the  coupling;  then  move  the  guiding  pul- 
leys to  their  proper  position  to  receive  the  cord,, 
and  the  instrument  is  in  readiness  for  use. 


34:  RICHARDS     STEAM-ENGINE   INDICATOR. 

II.    OF    GIVING   MOTION   TO    THE   PAPER. 

Tiie  Drum  the  best  Means. — The  revolution  of  a 
drum  is  probably  the  most  correct  as  well  as  con- 
venient method  of  giving  motion  to  the  paper.  It 
may  be  supposed  that  a  flat  slide,  worked  by  posi- 
tive means,  would  have  a  perfectly  accurate  motion; 
but,  in  fact,  at  high  velocities,  where  alone  any 
trouble  is  met  with,  the  difficulties  involved  in  its 
use  are  more  troublesome  than  those  presented  by 
the  cylinder.  In  most  cases  the  connecting-rod 
must  necessarily  be  somewhat  long;  it  must  not 
tremble,  or  the  line  on  the  paper  will  be  tremulous, 
:and  the  weight  required  for  stiffness,  joined  to  the 
weight  of  the  slide,  causes  a  momentum,  which,  if 
the  rod  is  worked  by  a  vibrating  arm,  will  give  fo 
the  paper,  on  each  centre,  a  motion  opposite  to 
that  of  the  piston  of  the  engine ;  and  precisely  at 
these  points  it  is  of  the  greatest  consequence  that 
the  two  motions  shall  coincide. 

In  the  use  of  the  'cylinder  at  any  speed,  the  ques- 
tion of  obtaining  a  positive  motion,  if  there  is  no 
-elasticity  in  the  cord  or  the  parts  to  which  it  is 
-connected,  is  simply  one  of  proportion  between  the 
momentum  of  the  revolving  parts  and  the  strength 
of  the  spring  by  which  this  is  resisted.  In  this  In- 
dicator these  parts  are  made  as  light  as  possible 
-consistently  with  other  requirements,  and  the 
spring  is  of  such  strength  that  they  may  be  reci- 
procated from  250  to  300  times  per  minute,  without 


RICHARDS'  STEAM-ENGINE  INDICATOR.  25 

any  increase  in  the  length  of  the  diagram,  and  of 
course,  therefore,  without  any  error  in  the  motion. 
There  is  no  difference  in  the  construction  of  these 
Indicators  in  this  respect,  it  being  intended  that 
every  instrument  shall  be  applicable  to  any  engine. 

From  what  Points  to  derive  the  Motion. — This  may 
be  taken  from  any  part  of  the  engine  which  has  a 
motion  coincident  with  that  of  the  piston.  For  a 
beam-engine  a  point  on  the  beam,  or  beam-centre, 
or  on  the  parallel-motion  rods  where  these  are  em- 
ployed, will  give  the  proper  motion;  but  care  must 
be  taken  that  the  cord  be  so  led  off,  that  when  the 
engine  is  on  the  half  stroke  it  will  be  at  right  angles 
to  whatever  gives  it  motion  (a  requirement  too 
often  omitted) ;  afterwards  its  direction  of  motion 
may  be  changed  as  required,  always  taking  care, 
however,  to  use  as  few  carrying  pulleys  as  possible, 
and  the  shortest  possible  cord,  which  should  be  of 
linen,  size  No.  3  ;  it  should  be  well  stretched  by 
suspending  a  weight  to  it  for  several  days. 

In  some  cases  it  is  most  convenient  to  take  the 
motion  from  a  point  on  the  end  of  the  revolving 
shaft ;  this  is  frequently  the  case  on  horizontal  en- 
gines, working  at  high  speeds,  because  then  the 
motion  does  not  need  to  be  reduced.  Exact  accu- 
racy cannot  be  got  in  this  way,  however,  without 
-employing  a  moving  slide,  and  connecting  it  with 
the  pin  in  the  end  of  the  shaft  by  a  rod  or  cord  of 
such  length  that  its  angular  vibration  shall  be  the 
2 


26  RICHARDS'  STEAM-ENGINE  INDICATOR. 

same  as  that  of  the  connecting-rod.  This  will  be 
found  generally  a  troublesome  matter;  and  the  en- 
gineer will  probably  prefer  in  most  .cases  to  disre- 
gard the  error  resulting  from  its  omission — which 
is,  that  the  motion  of  the  paper  will  be  more  near- 
ly equal  at  the  two  ends  of  the  stroke,  being  slower 
than  that  of  the  piston  at  the  one  end,  and  faster 
at  the  other.  The  crank  or  pin  from  which  the 
cord  receives  its  motion  must  be  on  its  centre  re- 
latively to  the  direction  of  the  cord,  whatever  that 
direction  may  be,  precisely  when  the  crank  of  the 
engine  is  on  Us  centre.  If  this  requirement  is  not 
carefully  attended  to,  the  diagram  will  be  worth- 
less. 

Q-enerally,  on  horizontal  engines,  the  motion  of 
the  paper  is  taken  from  the  cross-head.  In  an 
engine-room,  a  strip  of  board  may  be  suspended 
from  the  ceiling,  or  carried  off  horizontally  in  such 
a  manner  as  to  permit  it  to  swing  backward  and 
forward  edgeways  by  the  side  of  the  guides,  and 
motion  may  be  given  to  it  by  a  pin,  secured  firmly 
to  the  cross-head,  and  projecting  through  a  slot  in 
the  board,  in  which  it  should  fit  nicely  to  prevent 
lost  time  on  the  centres.  To  save  drilling  and 
defacing  the  cross-head  to  insert  a  pin,  we  use  a 
clamp  made  fast  to  the  cross-head  or  some  of  its 
appendages  by  a  set  screw  ;  a  projecting  pin  plays- 
in  a  slot  in  the  board,  or  if  preferred,  a  short  con- 
necting rod  may  be  used  to  make  the  connection. 
The  board  must  hang  plumb  when  the  piston  is  in 


RICHARDS'  STEAM-ENGINE  INDICATOR.  27 

the  middle  of  its  stroke,  or  if  horizontal  at  right 
angles.  The  cord  may  be  connected  to  this 
strip  of  board  at  a  point  sufficiently  near  to  its 
point  of  suspension  to  give  the  required  reduction 
of  motion  for  the  paper,  and  must  be  led  off  in  a 
horizontal  direction,  and  then  over  one  or  more 
pulleys  in  any  required  direction  to  the  Indicator. 
At  high  speeds,  however,  pulleys  should  be  avoided. 
On  portable  engines,  the  motion  may  be  attained  in 
the  manner  just  described,  the  lever  swinging  from 
a  pin  supported  in  a  standard  about  two  feet  in 
height,  set  on  one  of  the  guide-bars. 

On  locomotives  having  outside  connections,  the 
motion  must  be  taken  from  the  cross-head.  It  is 
indispensably  necessary  to  use  only  a  short  direct 
•cord,  free  from  elasticity,  and  connected  to  a  point 
the  motion  of  which  is  reduced  from  that  of  the 
cross-head  by  positive  means.  Care  must  be  taken 
also  so  to  proportion  the  parts  employed  for  this 
purpose,  that  the  point  at  which  the  cord  is  con- 
nected shall  have  a  positive  motion  without  any 
fling,  a  matter  not  by  any  means  free  from  difficulty 
at  250  revolutions  per  minute.  A  rock-shaft, 
turning  in  bushings,  supported  by  two  angle  iron 
standards,  precisely  over  the  mid-position  of  that 
point  of  the  cross-head  from  which  the  motion  is 
derived,  affords  perhaps  the  best  means  of  redu- 
cing the  motion.  A  long-arm  is  worked  by  the 
cross-head  and  a  short-arm  gives  motion  to  the 
cord.  The  short-arm  must  be  keyed  in  such  a  po« 


28  RICHARDS'  STEAM-ENGINE  INDICATOR. 

sition  that  when  the  piston  is  in  the  middle  of  its 
stroke  it  will  stand  at  right  angles  with  the  direc- 
tion of  the  cord,  whatever  that  may  be.  The  di- 
rection of  the  cord  may  form  any  necessary  angle 
with  the  horizontal  line,  but  must  be  at  right 
angles  with  the  rock-shaft. 

On  locomotives  having  inside  connections,  and 
a  single  pair  of  driving-wheels,  where  it  is  practi- 
cable, it  will  be  found  to  be  the  better  way  to  take 
the  motion  from  a  pin  set  in  the  end  of  the  shaft, 
and  to  communicate  it  by  a  connecting-rod  to  a 
point  convenient  for  attaching  the  cord.  The  parts 
should  be  all  substantially  made;  the  momentum  of 
the  connecting-rod  will  be  perfectly  resisted  by  the 
pin. 

On  oscillating  engines,  the  motion  may  be  taken 
from  the  brasses  at  the  end  of  the  piston-rod.  If 
the  stroke  is  long,  it  is  sometimes  difficult  to  re- 
duce this  motion  to  that  required  for  the  paper,  and 
in  such  cases  it  is  necessary  to  Jbake  the  motion 
from  an  eccentric  on  the  main  shaft,  to  a  point  as 
near  as  possible  to  the  trunnion,  and  thence  to 
communicate  it  to  the  Indicator.  In  all  these  con- 
nections, it  is  of  the  first  consequence  that  there  be 
no  lost  time,  which  will  require  to  be  made  up  on 
every  centre,  and  will  thus  cause  the  paper  to  stand 
still  while  the  piston  is  moving. 

Pulleys  of  different  diameters  on  the  same  spin- 
dle have  often  been  used  as  a  means  of  reducing 
the  motion  from  that  of  the  cross-head,  but  we  do 


RICHARDS'   STEAM-ENGINE   INDICATOR.  29 

not  recommend  them  ;  at  high  speeds  it  is  very 
difficult  to  make  them  answer.  The  experience  of 
the  careful  operator  will  teach  him  to  guard  against 
the  various  causes  of  error  here  mentioned,  and 
•others  which  will  arise  in  the  great  diversity  of  situ- 
ations in  which  the  Indicator  is  used,  and  the 
effects  of  which  are  the  more  mischievous  because 
often  the  diagram  itself  furnishes  no  means  of  de- 
tecting them.  The  mathematician  will  perceive 
that  perfect  accuracy  of  motion  is  attained  by  only 
a  very  few  of  the  methods  here  suggested.  Most 
of  them  are  only  approximately  accurate,  but  they 
are  the  best  which  can  be  readily  employed,  and 
the  errors  which  they  involve  are  too  slight  to  be 
of  practical  moment.  For  the  professional  engi- 
neer, of  course,  directions  are  unnecessary. 

IIL    HOW  TO  TAKE  A  DIAGRAM. 

To  fix  the  Paper. — Take  the  outer  cylinder  off 
from  the  instrument,  secure  the  lower  edge  of  the 
paper,  near  the  corner,  by  one  spring,  then  bend 
the  paper  round  the  cylinder,  and  insert  the  other 
<x>rner  between  the  springs.  The  paper  should  be 
long  enough  to  let  each  end  project  at  least  half  an 
inch  between  the  springs.  Take  the  two  project- 
ing ends  with  the  thumb  and  finger,  and  draw  the 
paper  down,  taking  care  that  it  lies  quite  smooth 
and  tightj  and  that  the  corners  come  fairly  together, 
and  replace  the  cylinder. 


30  RICHARDS'  STEAM-ENGINE  INDICATOR. 

To  connect  the  Cord. — The  Indicator  having  been 
attached,  and  the  correct  motion  obtained  for  the 
drum,  and  the  paper  fixed,  the  next  thing  is  to  see 
that  the  cord  is  of  the  proper  length  to  bring  the 
diagram  in  its  right  place  on  the  paper — that  is, 
midway  between  the  springs  which  hold  the  paper 
on  the  drum.  In  order  to  connect  and  disconnect 
readily,  the  short  cord  on  the  Indicator  is  furnished 
with  a  hook,  and  at  the  end  of  the  cord  coming* 
from  the  engine,  a  running  loop  may  be  rove  in  a 
thin  strip  of  metal,  in  the  manner  shown  in  the 
following  cut,  by  which  it  can  be  readily  adjusted 


to  the  proper  length,  and  taken  up  from  time  to 
time,  as  it  may  become  stretched  by  use.  On  high- 
speed engines,  it  is  as  well,  instead  of  using  this,  to 
adjust  the  cord  and  take  up  the  stretching,  as  it 
takes  place,  by  tying  knots  in  the  cord.  If  the  cord 
becomes  wet  arid  shrinks,  the  knots  may  need  to  be 
untied,  but  this  rarely  happens.  The  length  of  the 
diagram  drawn  at  high  speeds  should  not  exceed 
four  and  a  half  inches,  to  allow  changes  in  the  length 
of  the  cord  to  take  place  to  some  extent,  without 
causing  the  drum  to  revolve  to  the  limit  of  its  mo- 
tion in  either  direction.  On  the  other  hand,  the 
diagram  should  never  be  drawn  shorter  than  is 
necessary  for  this  purpose. 


lUCHARDS'    STEAM-ENGINE    INDICATOR.  31 

To  take  the  Diagram. — Everything  being  in  readi- 
ness, turn  the  key  of  the  stopcock  to  a  vertical  po- 
sition, and  let  the  piston  of  the  Indicator  play  for 
a  few  moments,  while  the  instrument  becomes 
warmed.  Then  turn  the  key  horizontally  to  the 
position  in- which  the  communication  is  opened 
between  the  under  side  of  the  piston  and  the 
atmosphere,  hook  on  the  cord  and  draw  the  atmos- 
pheric line.  Then  turn  the  key  back  to  its  vertical 
position,  and  take  the  diagram.  When  the  key 
stands  vertical,  the  communication  with  the  cylin- 
der is  wide  open,  and  care  should  be  observed  that 
it  does  stand  in  that  position  whenever  a  diagram 
is  taken,  so  that  this  communication  shall  not  be  in 
the  least  obstructed. 

To  apply  the  pencil  to  the  paper,  take  the  end  of 
the  longer  brass  arm  with  the  thumb  and  forefin- 
ger of  the  left  hand,  and  touch  the  point  as  gently 
as  possible,  holding  it  during  one  revolution  of  the 
engine,  or  during  several  revolutions  if  desired. 
There  is  no  spring  to  press  the  point  to  the  paper, 
except  for  oscillating  cylinders;  the  operator,  after 
admitting  the  steam,  waits  as  long  as  he  pleases 
before  taking  the  diagram,  and  touches  the  pencil 
to  the  paper  as  lightly  as  he  chooses.  Any  one,  by 
taking  a  little  pains,  will  become  enabled  to  per- 
form this  operation  with  much  delicacy.  As  the 
hand  of  the  operator  cannot  follow  the  motions  of 
an  oscillating  cylinder,  it  is  necessary  that  the  point 
be  held  to  the  paper  by  a  light  spring,  and  instru- 


32  RICHARDS'  STEAM-ENGINE  INDICATOR. 

ments  to  be  used  on  engines  of  this  class  are  fur- 
nished with  one  accordingly. 

Diagrams  should  not  be  taken  from  an  engine 
until  some  time  after  starting,  so  that  the  water 
condensed  in  warming  the  cylinder,  etc.,  shall 
have  passed  away.  Water  in  the  cylinder  in  ex- 
cess always  distorts  the  diagram,  and  sometimes 
into  very  singular  forms.  The  drip-cocks  should 
be  shut  when  diagrams  are  being  taken,  unless  the 
boiler  is  priming.  If  when  a  new  instrument  is 
first  applied  the  line  should  show  a  little  evidence 
of  friction,  let  the  piston  continue  in  action  for  a 
short  time,  and  this  will  disappear.* 

As  soon  as  the  diagram  is  taken,  unhook  the 
cord;  the  paper  cylinder  should  not  be  kept  in 
motion  unnecessarily,  it  only  wears  out  the  spring, 
especially  at  high  velocities.  Then  remove  the 
paper,  and  minute  on  the  back  of  it  at  once  as 
many  of  the  following  particulars  as  you  have  the 
means  of  ascertaining,  viz  : — 

The  date  of  taking  the  diagram,  and  scale  of  the 
Indicator. 


*  Thus,  by  the  motion  of  the  pencil  up  and  down,  and  the 
paper  from  right  to  left,  and  left  to  right,  we  transfer  the 
pressure  of  the  steam  and  vacuum  (if  there  be  any),  and  the 
movement  of  the  piston  to  the  paper,  giving  us  a  map  or  dia- 
gram of  the  action  required  to  move  the  load  at  any  and  all 
points  of  the  stroke,  from  which  the  power  exerted  may  be 
cc  mputed  and  the  condition  of  the  internal  action  seen. 


RICHARDS'  STEAM-ENGINE  INDICATOR.  33 

The  engine  from  which  the  diagram  is  taken, 
which  end,  and  which  engine,  if  one  of  a  pair. 

The  length  of  the  stroke,  the  diameter  of  the 
cylinder,  and  the  number  of  double  strokes  per 
minute. 

The  size  of  the  ports,  the  kind  of  valve  employed, 
the  lap  and  lead  of  the  valve,  and  the  exhaust  lead. 

The  amount  of  the  waste-room,  in  clearance  and 
thoroughfares,  adds  to  the  length  of  the  cylinder. 

The  pressure  of  steam  in  the  boiler,  the  diame- 
ter and  length  of  the  pipe,  the  size  and  position  of 
the  throttle  (if  any),  and  the  point  of  cut-off. 

On  a  locomotive,  the  diameter  of  the  driving- 
wheels,  and  the  size  of  the  blast  orifice,  the  weight 
of  the  train,  and  the  gradient,  or  curve. 

On  a  condensing-engine,  the  vacuum  by  the 
gauge,  the  kind  of  condenser  employed,  the  quan- 
tity of  water  used  for  one  stroke  of  the  engine,  its 
temperature  and  that  of  the  discharge,  the  size  of 
the  air-pump  and  length  of  its  stroke,  whether 
single  or  double  acting,  and,  if  driven  indepen- 
dently of  the  engine,  the  number  of  its  strokes  per 
minute,  and  the  height  of  the  barometer. 

The  description  of  boiler  used,  the  temperature 
of  the  feed-water,  the  consumption  of  fuel  and  of 
water  per  hour,  and  whether  the  boilers,  pipes,  and 
engine  are  protected  from  loss  of  heat  by  radiation, 
and  if  so  to  what  extent. 

In  addition  to  these,  there  are  often  special  cir- 
cumstances which  should  be  noted. 
2* 


34  RICHARDS'  STEAM-ENGINE  INDICATOR. 


IV.    HOW   TO    KEEP   THE  INDICATOR   IN    ORDER. 

Having  the  attachments  made;  before  we  admit 
steam  to  the  instrument,  we  open  the  cocks  and 
blow  through  the  connections  to  clear  them  from 
any  foreign  matter,  that  it  may  not  enter  and 
injure  the  instruments. 

The  Indicator  will  not  continue  to  work  well,  un- 
less it  is  kept  in  good  order.  When  used,  it  gene- 
rally becomes  filled  with  water,  which  will  rust  and 
thus  weaken  the  spring,  and  the  steam  often  con- 
tains impurities  and  grit,  a  portion  of  which  ia 
lodged  in  it.  After  the  Indicator  has  been  used, 
and  before  putting  it  up,  unscrew  the  cover  of  the 
cylinder  case,  and  draw  off  the  upper  ferule,  with 
the  pencil  movement  and  the  piston  and  spring  at- 
tached, empty  the  water  from  the  cylinder  case, 
carefully  clean  and  dry  all  the  parts,  and  replace 
them,  lubricating  the  cylinder  with  a  few  drops  of 
oil  which  is  entirely  free  from  gum.*  The  cylin- 

*  The  oil  is  very  important;  it  should  be  of  the  purest  kind, 
free  from  gum  and  all  foreign  matter.  The  porpoise  oil  we 
have  found  to  answer  all  the  requirements  ;  it  has  wonderful 
ability  to  resist  the  action  of  steam  and  water.  We  have 
found  the  cylinder  well  lubricated  after  having  taken  a  hun- 
dred diagrams.  It  has  equal  merit  in  preventing  corrosion; 
hence  it  should  be  used  on  the  springs,  piston-rod,  and  arms. 
It  costs  high,  but  a  small  bottle  of  it  will,  if  properly  used, 
last  for  years.  It  can  be  obtained  of  any  first-class  clock- 
maker  or  dealer  in  clock  materials.  * 


RICHARDS   STEAM-ENGINE  INDICATOR.  3.^ 

der  is  not  to  be  removed  from  the  case  under  any 
circumstances;  the  operation  above  directed  gives 
complete  access  to  it. 

Sometimes  the  surfaces  of  the  piston  and  cylinder 
become  scratched  or  roughened  by  impurities  in 
the  steam,  which  will  be  detected  at  once  in  the 
diagram  by  the  unsteadiness  of  the  line.  If  this 
shows  the  existence  of  any  obstruction  to  the  per- 
fectly free  action  of  the  Indicator,  take  the  instru- 
ment apart,  as  for  cleaning ;  take  out  the  two 
screws  at  the  top  of  the  piston-rod  connecting  it 
with  the  pencil  movement,  and  unscrew  the  spring 
from  the  piston  and  the  cover;  then  replace  the 
piston  in  the  cylinder,  after  cleaning  and  lubri- 
cating them;  screw  on  the  cover  to  guide  the  stem, 
and  rub  the  piston  up  and  down  in  the  cylinder, 
at  the  same  time  revolving  the  stem  between  the 
thumb  and  finger.  The  surfaces  will  quickly  wear 
each  other  smooth ;  no  grinding  or  polishing 
material  should  be  used;  the  piston  should  be  taken 
out  once  or  twice  during  the  operation,  and  the 
surfaces  cleaned.  The  piston,  if  dry,  ought  to  drop 
perfectly  free  from  every  position.  Before  re- 
placing, lift  the  levers,  and  let  them  fall,  to  see  if 
their  action  also  is  entirely  free.  Then  replace 
everything,  taking  care  to  screw  the  heads  of  the 
spring  firmly  up  to  the  piston  and  cover.  Before 
putting  the  piston  in  the  cylinder,  revolve  it  be- 
tween the  thumb  and  finger,  to  ascertain  if  the 
pins  connecting  it  with  the  pencil  movement  turn 


36  RICHARDS'  STEAM-ENGINE  INDICATOR. 

quite  smoothly  in  the  groove  at  the  end  of  the 
stem.  The  paper  cylinder  requires  to  be  lubri- 
cated occasionally  with  a  drop  or  two  of  pure  oil, 
applied  at  the  end  of  the  arbor,  also  the  leading 
pulleys  and  the  joints  of  the  pencil  movement. 

V.    HOW   TO   CHANGE   THE   SPRINGS. 

The  directions  already  given  for  taking  the  in- 
strument apart,  for  the  purpose  of  smoothing  the 
surfaces  of  the  cylinder  and  piston,  are  sufficient 
also  for  changing  the  spring.  Merely  introduce 
another,  instead  of  replacing  the  one  removed. 
The  lengths  of  the  springs  for  the  different  scales 
are  so  proportioned  to  each  other,  that  the  pencil 
will  always  come  to  the  proper  position  for  drawing 
the  atmospheric  line.  Be  careful  that  the  heads 
are  screwed  up  firmly  to  the  piston  and  cover. 

The  spring,  which  gives  reaction  to  the  paper 
cylinder,  is  liable  to  break  after  considerable  use, 
especially  on  engines  running  at  high  speeds  ; 
for  which  reason  this  cylinder  should  never  be  left 
to  run  unnecessarily.  When  this  happens,  a  new 
spring  can  be  readily  inserted,  as  follows.  Set  the 
Indicator  on  the  engine;  if  there  is  no  other  con- 
venient means  for  holding  it  firmly,  remove  the 
cover  of  the  spring  case  and  the  broken  spring; 
then  take  out  the  screw,  and  remove  the  brass  ring 
from  the  arbor.  Screw  the  new  spring  to  the 
brass  ring,  replace  this  on  the  arbor,  and  set  the 


RICHARDS'  STEAM-ENGINE  INDICATOR.  37 

screw  firmly  up  to  the  head.  Then  coil  the  spring 
into  the  case,  and  hook  the  end  on  the  rim ;  see 
tnat  it  is  coiled  in  the  same  direction  with  the  cord. 
If  the  spring  has  not  sufficient  strength  to  keep  the 
cord  quite  tight,  another  coil  must  be  given  to  it, 
but  it  should  not  be  coiled  any  tighter  than  is  ne- 
cessary for  this  purpose. 


HOW  TO  ASCERTAIN  THE  POWER  EXERTED  BY 
THE  ENGINE. 

The  custom  was  introduced  by  Watt,  and  has 
since  been  generally  followed  in  England,  to  desig- 
nate the  size  of  engines  in  measures  of  "  horse 
power."  Watt  ascertained  by  experiment  that  the 
power  of  London  draught  horses,  exerted  with  ordi- 
nary continuance,  was  to  lift  33,000  Ibs.  one  foot  in 
one  minute,  and  this  is  now  employed,  wherever 
English  measurements  are  used,  as  the  unit  of 
measurement  of  the  actual  power  of  steam  engines. 

The  Indicator  furnishes  one  of  the  data  for  ascer- 
taining the  power  exerted  by  the  steam-engine, 
namely,  the  mean  or  average  pressure  of  steam 
during  the  stroke,  on  each  square  inch  of  the 
piston  ;  or,  more  accurately,  the  excess  of  pressure 
on  the  acting  side  of  the  piston  to  produce  motion, 
over  that  on  the  opposite  side  to  resist  it.  This 
being  multiplied  into  the  whole  number  of  square 
inches,  and  the  product  by  the  mean  or  average 
speed  of  the  piston,  in  feet  per  minute,  gives  the 


38  RICHARDS'  STEAM-ENGINE  INDICATOR. 

total  number  of  pounds  of  force  acting  through  one 
foot  in  a  minute,  which  are  called  foot  pounds,  and 
by  dividing  this  by  33,000,  which  is  the  unit  for  a 
borse  power,  we  obtain  the  gross  power  of  the 
engine  in  actual  horse  powers. 

In  order  to  ascertain  the  effective  power,  how- 
ever, there  must  be  deducted  from  this  the  friction 
of  the  engine,  or  the  power  required  to  drive  the 
engine  alone  at  the  same  speed,  which,  except  in 
the  case  of  vessels  with  the  wheels  submerged,  the 
Indicator  generally  enables  us  to  ascertain  ;  and 
also  the  increase  in  this  friction  which  arises  when 
the  resistance  is  being  overcome,  which  the  Indi- 
cator does  not  show.  The  amount  of  this  latter  is 
not  generally  known  with  any  accuracy  ;  but  we 
know  that  the  percentage  of  loss  from  this  cause 
diminishes  as  the  size  of  the  engine  is  enlarged, 
because  the  increase  in  the  motion  of  the  surfaces 
in  contact  is  much  slower  than  the  increase  in  the 
area  of  the  piston,  and  also  that  it  varies  according 
to  the  nature  of  the  lubricating  material  employed, 
and  the  degree  of  completeness  attained  in  the 
separation  of  the  surfaces  by  means  of  it.  Five 
per  cent,  is  usually  allowed  for  this  increase  of 
friction;  but  it  may,  in  fact,  be  considerably  more 
or  less  than  this.  On  small  engines,  the  friction- 
brake  can  be  applied,  to  show  the  amount  of  effec- 
tive power  exerted,  and  a  comparison  of  this  with 
the  gross  power,  and  with  the  friction  of  the  engine 
alone,  as  shown  by  the  Indicator,  will  exhibit  the 
increase  of  friction  occasioned  by  different  amounta 


RICHARDS'  STEAM-ENGINE  INDICATOR.  3D 

of  resistance,  and  show  the  value  of  different  lubri- 
cants, and  the  utility  of  extended  wearing  surfaces. 
We  will  now  describe  the  mode  of  ascertaining 
from  the  diagram  the  mean  pressures  on  the  oppo- 
site sides  of  the  piston,  in  condensing  and  in  non- 
condensing  engines.  For  this  purpose,  divide  the 
diagram  into  any  desired  number  of  equal  parts, 
by  lines  drawn  perpendicular  to  the  atmospheric 
line.  Sometimes  these  divisions  are  made  very 
numerous;  but  the  usual  practice  is  to  make  ten, 
which  number  is  probably  sufficient,  unless  great 
accuracy  is  desired,  when  twenty  divisions  may  be 
made.  A  convenient  instrument  for  facilitating 
this  operation,  saving  time,  and  insuring  accuracy, 
is  furnished  with  these  Indicators.  It  consists  of  a 
parallel  ruler,  of  eleven  bars  of  thin  steel,  and  a 
small  square.  The  perpendiculars  are  first  drawn 
by  the  square  at  each  end  of  the  diagram,  when, 
the  outer  edge  of  bar  No.  1  being  brought  to  the 
beginning,  and  the  inner  edge  of  bar  No.  11  to  the 
termination  of  the  stroke,  the  dividing  lines  are 
drawn  with  a  sharp-pointed  pencil.  If  twenty 
divisions  are  desired,  the  intermediate  lines  for  this 
purpose  will  also  be  readily  drawn  by  means  of 
this  instrument,  points  being  first  marked  in  the 
middle  of  the  outer  divisions.  It  is  an  excellent 
practice  to  divide  the  diagram  also  by  lines  drawn 
parallel  with  the  atmospheric  line,  into  equal 
divisions,  each  representing  a  certain  number  of 
pounds  pressure,  generally  five  or  ten,  and  num- 


40  RICHARDS'  STEAM-ENGINE  INDICATOR. 

bered  on  the  margin  according  to  the  scale  of  the 
Indicator  ;  by  which  means  the  engineer  is  able  to 
observe  much  more  accurately  the  general  nature 
of  the  diagram.  The  same  instrument  may  be 
employed  for  this  purpose. 

On  diagrams  from  condensing  engines,  the  line  of 
perfect  vacuum  should  be  drawn  at  the  bottom, 
and  the  line  of  the  boiler  pressure,  as  shown  by  the 
gauge,  at  the  top.*  The  line  of  perfect  vacuum 
varies  in  its  distance  from  the  atmospheric  line,  or, 
more  correctly,  the  latter  varies  in  its  distance 
from  the  former,  according  to  the  pressure  of  the 
atmosphere,  as  shown  by  the  barometer,  from 
13 . 72  Ibs.  on  the  square  inch  when  the  mercury 
stands  at  28  inches,  to  15 . 19  Ibs.  when  it  stands  at 
31  inches  (vide  Table  II.);  and  it  should  be  drawn 
according  to  the  fact,  if  this  can  be  ascertained. 
The  engineer  should  always  have  a  good  aneroid 
in  his  pocket.  The  pressure  of  the  atmosphere  is 
usually  reckoned  at  15  Ibs.,  which,  as  a  general  rule, 
is  too  high,  being  correct  only  when  the  barometer 
stands  at  30.6  inches ;  but  the  error  is  unimpor- 
tant, and  it  is  very  convenient  to  avoid  the  use  of 
a  fraction,  and  to  say  that  30  Ibs.,  45  Ibs.,  60  Ibs., 

*  When  accuracy  is  required,  the  steam-gauge  should  be 
tested  by  the  Indicator,  which  may  be  done  by  stopping  the 
engine  on  the  centre,  opening  the  steam-valve,  and  letting 
the  full  pressure  on  the  instrument;  when  the  indications  of 
the  two  instruments  may  be  compared  and  noted. 


41 

and  so  on,  represent  2,  3,  4,  5,  6  atmospheres  of 
pressure. 

The  principal  object  of  knowing  the  exact  pres- 
sure of  the  atmosphere  is,  to  ascertain  the  duty 
performed  by  the  condenser  and  air-pump.  The 
temperature  of  the  discharge  being  known,  the 
pressure  of  vapor  inseparable  from  that  tempera- 
ture is  also  known  (vide  Table  No.  HI.),  and  this 
being  deducted  from  the  actual  pressure  of  the 
atmosphere,  the  remainder  is  the  total  attainable 
vacuum  at  that  temperature. 

The  areas  of  the  diagram  above  and  below  the 
atmospheric  line  are  usually  calculated  separately, 
to  ascertain  how  effectually  the  resistance  of  the 
atmosphere  is  removed  from  the  non-acting  side  of 
the  piston,  by  those  parts  of  the  engine  whose  func- 
tion this  is.  In  case  of  engines  working  very  ex- 
pansively, however,  the  expansion  curve  crosses 
the  atmospheric  line,  and  sometimes  at  an  early 
point  of  the  stroke,  as  in  diagram  No.  10.  In  such 
cases,  the  whole  space  between  the  atmospheric 
line  and  the  line  of  counter-pressure  should  be 
credited  to  the  condenser  and  air-pump  ;  not,  of 
course,  to  be  considered  in  estimating  the  power 
exerted,  but  for  ascertaining  the  degree  of  economy 
in  the  consumption  of  steam,  which  depends  greatly 
on  the  amount  of  vacuum  maintained. 

The  lines  having  been  accurately  drawn  as  above 
directed,  ascertain,  by  careful  measurement  with 
the  scale,  the  mean  pressure  in  each  division,  be- 


42  RICHARDS'  STEAM-ENGINE  INDICATOR. 

tween  the  atmospheric  line  and  the  upper  line  of 
the  diagram,  until  this  crosses  the  former,  if  it  does 
so;  add  these  together,  and  point  off  one  place  cf 
decimals,  or  divide  their  sum  by  the  number  of 
divisions,  if  there  are  more  than  10,  and  the  quo- 
tient will  be  the  mean  pressure  above  the  atmos- 
phere during  the  stroke.  Then  repeat  the  process 
for  the  area  between  the  atmospheric  line,  or  the 
expansion  curve  after  it  has  crossed  this  line,  and 
the  lower  outline  of  the  diagram.  Add  the  two 
mean  pressures  so  ascertained  together,  then  find 
in  Table  No.  I.  the  number  of  square  inches  in  the 
surface  of  the  piston,  if  you  know  the  diameter, 
and  multiply  the  pressure  on  one  square  inch  by 
the  number  of  square  inches,  and  the  product  by 
the  mean  velocity  of  the  piston,  in  feet  per  minute, 
and  divide  by  33,000,  and  the  quotient  will  be  the 
gross  amount  of  horse-power  exerted  ;  or  the 
power  represented  by  the  two  areas  of  the  dia- 
gram, above  and  below  the  atmospheric  line,  may 
be  calculated  separately. 

[Since  the  publication  of  the  First  Edition,  my  attention 
has  been  called  to  an  improved  method  of  measuring  the  dia- 
gram which  is  more  expeditious  and  less  liability  to  error.  ] 

Thus,  your  diagram  is  divided  into  equal  parts  as 
usual — say  10.  Now,  we  take  a  narrow 'slip  of  paper, 
or  what  is  better,  card-board  that  is  thin  and  smooth; 
this  we  place  across  the  diagram  as  we  would  the 
scale,  letting  the  end  of  it  be  exactly  over  the  base 
line  ;  then  with  a  sharp-pointed  knife  prick  the  slip 


EICHARDS'    STEAM-ENGINE   INDICATOR.  43 

40* 

exactly  over  the  line  opposite  the  base  (steam-line), 
advance  the  slip  to  the  next  division,  and  carrying 
the  point  made  by  the  knife  to  the  base  line,  then 
remove  the  knife  and  make  another  prick  exactly 
over  the  line  opposite.  Repeat  the  movement  until 
you  have  measured  each  space  ;  then  make  a  mark 
with  your  pencil.  Now,  with  a  rule,  you  measure 
the  distance  from  the  end  of  the  slip  to  your  pencil 
mark  ;  we  will  assume  that  it  is  6J  inches.  Now,  as 
you  have  measured  10  spaces,  to  get  the  average,  we 
divide  it  by  10  ;  thus,  6J  expressed  decimally  is  6.25. 
This,  divided  by  10,  is  equal  to  .625. 

Now  the  scale  of  the  diagram  we  will  assume  to  be 
40  to  one  inch.  We  then  multiply  .625  by  the  scale, 
which  we  have  assumed  to  be  40,  and  we  get  the  fol- 
lowing result  as  an  average  pressure  per  square  inch  : 

.625 
40 

25.000  Ibs.  pressure. 

Expressed  in  arithmetical  signs,  it  is 

6.25  -=-  10  =  .625  x  40  =  25.000. 

Should  there  be  more  or  less  than  10  divisions  of 
the  diagram,  divide  by  the  number,  whatever  it  is. 
Should  the  scale  of  the  instrument  be  other  than  40, 
then  multiply  by  the  number,  whatever  it  may  be. 

This  mode  is  much  less  liable  to  error  than  the 
ordinary  mode  ;  in  fact,  it  reduces  the  liability  as  ten 
to  one.  It  is  more  expeditious,  in  so  much  as  it  saves 
the  additions  of  a  long  column  of  figures. 

The  space  between  the  steam  line  and  the  line  of 
boiler  pressure  shows  how  much  the  pressure  is 


44:  RICHARDS'  STEAM-ENGINE  INDICATOR. 

reduced  in  the  cylinder  by  throttling,  or  by  the  in- 
sufficient area  of  the  ports,  proper  allowance  being 
made  for  the  difference  of  pressure  necessary  to 
give  the  rapid  motion  to  the  steam,  and  that  be- 
tween the  line  of  counter-pressure  and  the  line  of 
perfect  vacuum  shows  the  amount  of  resistance  to 
the  motion  of  the  piston. 

In  illustration  of  the  foregoing  directions,  let  it 
be  required  to  find  the  effective  power  exerted  by 
the  pair  of  engines,  from  the  upper  end  of  one  of 
which  diagram  No.  1  was  taken,  the  diameter  of 
cylinder  being  95",  the  stroke  of  the  piston  10',  and 
the  number  of  revolutions  15  per  minute.  We  will 
assume  that  the  other  engine  would  have  given  the 
same  diagram,  which  is  possibly  correct,  and  also 
that  the  lower  ends  of  the  cylinders  would  have 
given  the  same,  which  is  probably  quite  incorrect, 
because  in  side-lever,  or  beam  engines,  the  speed  of 
the  piston  at  the  lower  end  is  slower,  and  therefore 
probably  the  pressure  obtained  is  greater,  than  in 
the  upper  end,  the  motion  of  the  valves  being  the 
same. 

The  mean  pressure  of  steam  above  the  atmosphere 

was 9.82  Ibs. 

The  average  vacuum  was 11 .4.6  " 

Total  excess  of  pressure  above  the  resistance  was.  21.28  " 

The  better  mode  of  calculation  in  all  cases  is,  to 
obtain  first  the  number  of  horse-powers  for  1  Ib.  to 
mean  pressure  on  the  square  inch,  as  follows  : 


RICHARDS*   STEAM-ENGINE  INDICATOR.  45 

Multiply  the  number  of  square  inches  in  the 

surface  of  the  piston 7088 . 2 

By  the  speed  of  the  piston  in  feet  per  minute.          300 


33.  (000)2126(460. 0(61 44 
198 
146 
132 
144 
132 
"126 

Which  is  the  number  of  horse-powers  exerted,  for 
each  pound  of  pressure  during  the  stroke  on  1  square 

inch  of  the  piston 64.44 

To  obtain  the  gross  power  we  multiply  this  by  the 

average  pressure  per  square  inch  on  the  piston 21 .28 

"51552 

•  12888 

6444 
12888 
Gross  horse-powers  exerted  in  one  engine  ....  1371 .2832 

To  obtain  the  effective  power  we  must  ab- 
stract from  the  multiplier 21 . 28  Ibs. 

The  pressure  required  to  run  the  engine 
alone,  which  in  so  large  an  engine 
would  probably  not  exceed 1 .00  Ib. 

And  the  increase  in  this  pressure  required 
to  overcome  the  increased  friction  when 
the  resistance  is  being  overcome,  say  5 

per  cent =1.06  " 

2.061ba 

Effective  pressure  on  each  square  inch ....  1& . 22   " 

Which  multiplied  by 64.44 

7688 
7688 
7688 
11532 

Gives  amount  of  effective  horse-power  ...          1238.5368 
Which  multiplied  by 2 

Gives 2,477.0  horse- 
power as  the  effective  power  of  the  engines. 


4(5  RICHARDS'  STEAM-ENGINE  INDICATOR. 

It  will  be  observed  that,  by  the  above  mode  of 
calculation,  we  obtain  for  any  engine,  the  speed  of 
piston  continuing  the  same,  a  constant  number, 
which,  multiplied  by  the  mean  pressure  on  a  square 
inch,  gives  at  once  the  amount  of  horse-power 
exerted  at  any  time. 

On  diagrams  from  non-condensing  engines,  the  line 
of  boiler  pressure  should  be  drawn  at  the  top,  and 
it  is  well  to  draw  the  line  of  perfect  vacuum  also, 
that  the  engineer  may  be  able  to  see  at  a  glance  the 
quantity  of  steam  consumed,  and  to  compare  with 
it  the  amount  of  work  done.  It  is  not  possible  that 
the  back  pressure  resisting  the  motion  of  the  piston 
shall  be  less  than  the  pressure  of  the  atmosphere, 
but  it  may  be  a  great  deal  more,  and  very  commonly 
in  non-condensing  engines  the  line  of  resistance  is 
as  much  as  2  or  3  Ibs.  above  the  atmospheric  line, 
though  it  is  quite  possible  to  avoid  this  excess 
altogether,  as  is  shown  in  diagrams  Nos.  6  and  9. 

The  mean  pressure  is  ascertained  in  the  manner 
already  directed  for  obtaining  the  pressure  in  con- 
densing engines  above  the  atmospheric  line,  and 
the  power  is  calculated  in  the  same  way. 

For  example,  let  it  be  required  to  find  the  effec- 
tive power  exerted  by  the  engine  from  which 
diagram  No.  6  was  taken,  the  diameter  of  the  cyl- 
inder being  18",  the  stroke  of  the  piston  42",  and 
the  number  of  revolutions  60  per  minute 


BICHAKDS     STEAM-ENGINE   INDICATOR.  47 

The  mean  pressure  of  steam  during  the 
stroke,  above  the  resistance  of  the  at- 
mosphere, was 25  Ibs, 

From  this  we  must  subtract  the  pressure 
required  to  run  the  engine  alone,  say. .  1.75  Ibs. 

And  the  increase  of  pressure  required  to 
overcome  the  increased  friction  when 
the  load  is  on,  estimated  at  5  per  cent. .  1.25  " 

3  Ibs. 

Leaving  effective  pressure 22  " 

The  area  of  the  piston  is 254.5  square  inches, 

Which,  multiplied  by  the  velocity  of 
the  piston 420  feet  per  minute, 

50900 
10180 


And  divided  by  33.  (000)106(890.0(3. 24 
99 


78 


129 
132 

Gives  3.24  horse-powers,  for 
each  pound  of  pressure  on 
1  square  inch  during  the 

stroke 3.24  horse-powers, 

Multiplied  by 22  Ibs.  pressure, 

648 
648 

Gives 71 . 28  effective  horse-powers, 

assuming  the  pressure  on  the  opposite  side  of  the 
piston  to  have  been  the  same. 


48  RICHARDS     STEAM-ENGINE   INDICATOR. 

In  the  same  manner,  on  stationary  engines,  the 
power  shown  by  the  frictional  diagrams  can  be 
calculated,  and  by  diagrams  taken  when  the  shaft- 
ing only  is  being  driven,  and  when  greater  or  lesser 
proportions  of  the  whole  resistance  are  being  over- 
come, and  on  vessels  at  different  depths  of  immer- 
sion. 

Generally,  engines  will  give  the  same  figures  at 
each  revolution,  the  pencil  retracing  the  same  line 
so  long  as  the  resistance  continues  the  same  ;  but 
sometimes  this  is  not  the  case,  as  in  the  engine 
from  which  the  diagram  just  calculated  was  taken, 
where  are  shown  four  distinct  expansion  curves. 
In  such  cases  care  must  be  taken  to  obtain  the 
average  diagram.  Also,  in  comparing  the  pressures 
required  to  overcome  different  resistances,  it  is  es- 
sential that  the  speed  of  the  engine  in  each  case  be 
the  same,  a  requirement  often  disregarded. 

In  all  calculations  of  power  from  the  diagram,  it 
is  assumed,  and  correctly  so,  that  the  value  of  each 
unit  of  motion  of  the  piston  is  the  same,  whether 
measured  at  the  extremes  or  in  the  middle  of  the 
stroke.  The  motion  of  the  crank  should  be  uni- 
form; and  if  this  is  the  case,  the  divisions  of  the 
time  occupied  in  a  revolution  can  be  accurately 
measured  on  the  circle  which  it  describes.  The 
motion  of  the  piston,  on  the  contrary,  changes  at 
every  point  of  the  stroke.  At  the  instant  when  the 
crank  is  on  the  centre  it  is  at  rest;  then  its  speed, 
at  first  infinitely  slow,  becomes  gradually  acceler^ 


RICHARDS   STEAM-ENGINE  INDICATOR.  3 

ated,  until,  at  the  point  where  the  direction  of  mo- 
tion of  the  piston  and  that  of  the  crank-pin  coin- 
cides, the  velocities  of  the  two  are  equal,  and  for 
some  distance  before  reaching  and  after  passing 
this  point  they  differ  but  little  ;  then  its  motion  is 
gradually  retarded,  until  on  the  opposite  centre  it 
is  at  rest  again. 


TO  MEASURE  FROM  THE  DIAGRAM  THE  AMOUNT 
OF  STEAM  CONSUMED. 

For  this  purpose,  draw  the  line  of  perfect  vacu- 
um, if  not  precisely  known,  at  14.7  Ibs.  below  the 
atmospheric  line.  Ascertain  how  much  the  clear- 
ance and  the  thoroughfare  add  to  the  length  of  the 
cylinder  at  one  end,  and  add  a  proportionate  quan- 
tity to  the  length  of  the  diagram  by  a  line  drawn 
perpendicular  to  the  atmospheric  line,  at  the  proper 
distance  from  the  admission  line.  Then  ascertain 
the  point  in  the  stroke  at  which  the  steam  is 
released,  and  the  pressure  in  the  cylinder  at  that 
point.  Multiply  this  pressure,  reckoned  from  the 
line  of  perfect  vacuum  (and  which  must  be  taken 
before  the  exhaust-port  has  been  opened),  by  the 
sectional  area  of  the  cylinder  in  square  inches,  and 
the  product  by  the  length  of  the  stroke  in  inches, 
up  to  the  point  at  which  the  steam  was  released, 
and  including  the  addition  for  the  clearance  and 
thoroughfare,  and  divide  by  14.7,  and  the  quotient 
will  be  the  number  of  cubic  inches  of  steam,  at  the 


60  RICHARDS'  STEAM-ENGINE  INDICATOR. 

pressure  of  the  atmosphere,  discharged  from  the 
cylinder  at  a  single  stroke.  If  the  valves  do  not 
leak,  and  there  is  no  water  with  the  steam,  the  cubic 
contents  of  the  cylinder  multiplied  by  the  pressure, 
at  the  point  of  cut-off,  should  equal  the  cubic  con- 
tents multiplied  by  the  pressure,  at  the  point  of 
release,  and  in  a  compound  engine  the  cubic  con- 
tents of  each  cylinder  multiplied  by  the  pressure, 
at  the  point  of  release,  should  give  the  same  result. 
Multiply  this  by  the  number  of  strokes  in  an  hour, 
and  divide  the  product  by  1728  to  reduce  the  cubic 
inches  to  cubic  feet,  and  the  quotient  again  by  1700, 
to  reduce  the  steam  at  atmospheric  pressui  a  to 
water,  and  the  result  will  be  the  number  of  cubic 
feet  of  water  used  per  hour;  multiply  this  by  62.5 
for  pounds,  and  divide  the  product  by  8.33  Ibs.  for 
wine  gallons.  The  supply  of  water  to  the  boilers 
will  need  to  be  greater  than  the  quantity  thus  ascer- 
tained, and  the  excess  required  will  measure  the 
aggregate  loss  from  all  causes,  including  leakage, 
priming,  blowing  off,  and  radiation  from  the  cylin- 
der and  pipes  where  the  water  of  condensation  does 
not  flow  back  into  the  boiler.  It  is  essential,  of 
course,  that  the  diagram  measured  shall  represent 
the  uniform  power  exerted,  or  the  mean  power,  if 
it  is  subject  to  variations. 

The  detection  in  this  manner  of  losses  of  heat, 

from  occult  causes,  is  one  of  the  most  remarkable 

and  important  services  which  have  been  rendered  by 

the  Indicator.     It  has  been  proved  in  some  cases 

3 


RICHARDS'  STEAM-ENGINE  INDICATOR.  51 

that  nearly  or  quite  twice  the  volume  of  steam 
must  have  entered  the  cylinder  at  every  opening 
of  the  ports,  either  in  the  form  of  steam  or  of  water 
already  condensed,  that  existed  in  the  form  of 
steam  at  the  point  of  cut-off.  The  field  here  pre- 
sented is  one  of  the  most  useful  in  which  the  Indi- 
cator can  be  employed. 

OBSERVATIONS  ON  THE  SEVERAL    LINES  OF  THE 
DIAGRAM. 

In  order  to  point  out  clearly  the  principal  points 
of  excellence  and  defect  in  the  action  of  engines, 
which  are  made  known  by  the  Indicator,  it  will  be 
best  to  consider  each  line  of  the  diagram  separately, 
beginning  at  the  commencement  of  the  stroke.  . 

I.     THE  ADMISSION-LINE. 

At  low  pressures  of  steam  this  line  may  be  very 
nearly  vertical,  especially  when  the  opening  of  the 
ports  is  preceded  by  considerable  compression  of 
the  steam  in  the  cylinder,  as  in  diagram  No.  1. 
Diagram  No.  13,  also  taken  from  a  celebrated 
steamship,  shows  a  more  gradual  opening,  but  not 
preceded  by  any  compression.  At  high  pressures 
it  is  important  to  avoid  the  shock  of  the  full  force 
of  the  steam  on  the  centre,  especially  when  there 
has  been  no  compression.  Diagrams  Nos.  6  and  7, 
from  non-condensing  engines,  show  a  moderate 
advance  of  the  piston,  and,  the  former  especially,  a 


52  RICHARDS'  STEAM-ENGINE  INDICATOR. 

• 

considerable  movement  of  the  orank,  while  the  pres- 
sure was  being  attained  in  the  cylinder,  the  latter 
with  and  the  former  without  precedent  compres- 
sion. These  are  all  excellent  admission-lines. 

The  direction  of  this  line  is  determined  by  the 
amount  of  lead  given  to  the  valve,  for  which  no 
general  rule  can  be  laid  down.  It  depends  upon 
the  speed  of  the  piston,  the  proportion  between  the 
area  of  the  ports  and  that  of  the  cylinder,  the 
rapidity  or  slowness  of  the  opening  movement,  and 
the  density  of  the  steam  already  in  the  cylinder  at 
the  instant  of  opening.  The  proper  lead  can  be 
ascertained  only  by  the  application  of  the  Indica- 
tor. Without  its  assistance  the  best  judgement  is 
liable  to  err  in  a  case  presenting  novel  conditions. 
By  the  best  judgment  is  meant  a  judgment  formed 
by  careful  comparison  of  the  lead  given  with  the 
admission-line  drawn  by  the  Indicator,  in  a  wide 
diversity  of  cases. 

II.     THE  STEAM-LINE. 

Here  we  find  engines  divided  into  four  classes, 
namely — 

1.  Those  in  which  the  valves  have  an  invariable 
motion,  without  any  or  with  only  very  trifling  lap, 
causing  the  port  to  remain  open,  or,  technically, 
the  steam  to  follow  the  piston,  quite  or  nearly  to 
the  envl  of  the  stroke. 


lUCHAKDS'    STEAM-ENGINE   INDICATOR.  53 

2.  Those  in  which  the  valves  have  also  an  in- 
variable motion,  but  with  more  or  less  lap,  causing 
the  steam  to  be  cufc  off  at  a  certain  fixed  point  of 
the  stroke. 

3.  Those  in  which  the  point  of  cut-off  may  be 
varied  by  hand,  either  by  means  of  the  link  motion 
or  of  an  independent  cut-off  gear;  and, 

4.  Those  in  which  the  point  of  cut-off  is  adjusted 
by  the  action  of  the  governor,  according  to  the 
changes  either  in  the  pressure  of  steam  or  the  re- 
sistance to  be  overcome. 

In  the  first  two  classes,  when  less  than  the  full 
pressure  is  required  in  the  cylinder,  the  governor 
or  the  engineer  adjusts  the  pressure  by  changing 
the  position  of  the  regulating  valve.  In  the  third 
class  the  regulating  valve  may  be  employed  for  this 
purpose,  but  the  more  usual  and  better  way  is  to 
run  such  engines  with  this  valve  entirely  open,  and 
to  adjust  the  mean  pressure  in  the  cylinder  by 
changing  the  point  of  cut-off.  Engines  of  the  fourth 
class  have  no  regulating  valve,  but  the  full  attain- 
able pressure  of  steam  is  admitted  to  the  cylinder. 

The  action  of  the  regulating  valve  varies  the  po- 
sition of  the  steam  line  upward  or  downward,  to 
that  distance  from  the  atmospheric  line  which  gives 
the  mean  pressure  required.  The  action  of  the 
cut-off  gear,  on  the  contrary,  varies  its  length  for 
the  same  purpose.  In  engines  in  which  the  steam 
follows  to  the  end,  or  nearly  to  the  end,  of  the 


51  RICHARDS'    STEAM-ENGINE    INDICATOR. 

stroke,  and  indeed  in  all  cases  where  the  pressure 
is  reduced  between  the  boiler  and  cylinder  by  the 
action  of  the  regulating  valve,  it  is  a  matter  of  very 
little  interest  what  the  steam-line  may  be.  Not 
only  its  distance  from  the  atmospheric  line,  but 
also  its  direction,  is  changed  by  every  change  in 
the  position  of  the  regulating  valve,  so  that  it  is 
not  at  all  a  fit  subject  for  consideration. 

In  engines  which  have  no  regulating  valve,  or 
where  it  is  not  employed,  as  in  marine  engines  ex- 
cept in  rough  weather^  the  steam -line  should  ap- 
proach nearly  to  the  line  of  boiler  pressure,  and 
should  be  parallel  with  this  line  up  to  the  point  of 
release  or  cut-off.     Diagrams  Nos.  1,  6,  8,  9,  afford 
examples  of  correct  steam-lines,  except  that  in  No. 
1  it  is  not  continued  parallel  nearly  up  to  the  point 
of  cut-off.     Diagram  No.  10  shows  a  slight  fall  of 
the   steam-line   as  the   piston   advanced,  but  the 
point  of  cut-off  is  well  shown.      Diagram  No.  12 
from  a  marine  condensing  engine,  at  336  feet  travel 
of  piston  per  minute;  and  Nos.  2,  3, 4,  and  5,  from 
a  locomotive,  at  730,  820,  and  950  feet  travel  of  pis- 
ton per  minute,  afford,  on  the  contrary,  examples 
of  bad  steam-lines.     The  boiler  pressure  is  very  near- 
ly attained  at  the  commencement  of  the  stroke,  in 
the  first  case,  by  lead  given  to  the  valve,  and  in 
others   by  lead  superadded  to  excessive  compres- 
sion ;  but  as  the  piston  advances,  the  pressure  falls 
with  great  rapidity,   and   the   point   at  which  the 
port  was  closed  there  is  no  means  of  discovering. 


RICHARDS'  STEAM-ENGINE  INDICATOR.  55- 

In  all  these  cases  the  passage  of  steam  to  the  valve- 
chamber  was  entirely  unimpeded.     Diagrams  Nos^ 
15  and  16   are   good   admission  and   steam  lines. 
Locomotive  -diagrams  Nos.  19,  20,  and  21,  are  re- 
markably good  steam  and  admission  lines.     In  No. 
22,    steam-line   falls   off    slightly.      The   nature   of 
the  steam-line  depends  principally  on  the  propor- 
tion between  the  area  of  the  ports,  supposing  them 
to  be,  as  they  ought,  the  smallest  passages  through 
which  the  steam  is  taken,  and  the  cubical  capacity 
of  cylinder  to  be  filled  in  a  given  time.     A  given 
cubical  capacity  may  be  formed  in  the  same  time- 
by  the  slow  advance  of  the  piston  in  a  larger  cylin- 
der, or  by  its  more  rapid  advance  in  a  smaller  one. 
The  sectional  area  of  cylinder  and  the  speed  of  the 
piston  must  be  equally  considered  in  determining" 
the  area  of  the  ports,  as  they  are  equal  elements  irt 
determining  the  capacity  of  cylinder  to  be  filled. 

While,  therefore,  very  high  velocity  of  piston 
does  not  render  impossible  the  attaining  of  a  cor- 
rect steam-line,  still  the  size  of  port  required  for 
this  purpose  becomes  so  considerable,  and  the- 
amount  of  power  absorbed  in  working  the  valves, 
under  the  pressure  which  is  generally  associated 
with  high  speed  of  piston,  is  already  so  serious,  that 
with  the  present  form  of  valve  in  use — on  locomo- 
tives, for  example — it  is  better  probably  to  submit 
to  the  defect  at  high  velocities,  than  to  attempt  to 
mend  it  by  enlargement.  Improvement  in  this  fea- 
ture can  be  looked  for  only  from  a  radical  change 


RICHARDS     STEAM-ENGINE   INDICATOR. 

in  the  valves  and  movements.  It  should  be  ob- 
served, however,  that  the  velocity  of  piston  at 
which  diagrams  Nos.  7  and  8  were  drawn  was  600 
feet  per  minute.  Another  cause  often  contributes 
largely  to  injure  the  steam-line,  especially  in  con- 
densing engines — namely,  the  condensation  of  the 
steam  on  entering  the  cylinder  ;  and  to  this  the 
enormous  fall  of  pressure  in  diagram  No.  11  must 
undoubtedly  be  in  part  attributed,  the  smallness 
of  the  ports  not  being  sufficient  to  account  for  it. 

There  is  obviously  a  point  beyond  which  expan- 
sion can  not  be  advantageously  carried,  because  it 
is  possible  to  cut  the  steam  off  so  early  that  even 
with  the  highest  pressure  the  engine  will  not  per- 
form any  duty  at  all,  but  only  run  itself.  Of  course 
the  power  absorbed  in  running  the  engine  should 
be  only  a  small  percentage  of  the  gross  power  ex- 
erted. But  there  is  also  another  limitation.  The 
loss  of  heat  by  radiation  and  conduction,  external 
and  internal,  is  far  greater  than  was  till  lately  gen- 
erally supposed.  It  is  possible  to  protect  pretty 
thoroughly  against  external  radiation  ;  but  against 
internal  radiation,  which  is  so  much  greater  than 
the  other,  as  the  capacity  for  heat  of  the  exhaust 
steam,  at  the  density  it  may  have,  is  greater  than 
that  of  the  atmosphere,  it  is  not  possible  to  protect 
at  all,  and  the  earlier  the  steam  is  cut  off,  the 
greater  is  the  proportionate  time  during  which  the 
exposed  surfaces  are  being  cooled,  and  the  smaller 
the  quantity  of  steam  admitted  from  which  they 


RICHARDS'    STEAM-ENGINE   INDICATOR.  57 

must  be  warmed  again.*  The  phenomenon  of  a 
higher  terminal  pressure,  in  cylinders  working 
steam  expansively,  than  the  law  of  the  gases  could 
account  for,  was  generally  explained,  until  quite  re- 
cently, by  supposing  that  the  valves  leaked  ;  but 
when  it  was  found  to  be  universal,  and  to  be  most 
remarkable  where  the  steam  was  most  charged 
with  moisture,  thoughtful  men  were  not  long  in  de- 
tecting the  true  cause.  The  temperature  of  this 
moisture,  as  it  enters  the  cylinder,  is  the  same  as 
that  of  the  steam,  and  being  in  great  part  relieved 
from  pressure  by  the  expansion,  it  will  instantly 
assume  the  gaseous  form,  provided  the  heat,  which 
must  be  rendered  latent  on  its  change  of  state,  is 
furnished.  This  is  abstracted  from  the  surfaces 
with  which  the  particles  of  moisture  come  in  con- 
tact, and  the  excess  of  terminal  pressure  above 
that  which  should  exist  measures  the  heat  thus 
lost,  and  which  must  be  regained  at  the  commence- 
ment of  the  next  stroke  from  the  entering  steam. 
If  the  steam  enters  the  cylinder  nearly  dry,  this 
process,  when  the  cylinder  becomes  heated,  soon 
reaches  a  very  moderate  point,  as  is  illustrated  in 
diagram  No.  6,  where  the  theoretical  curve  is  closely 
approximated  to.  Diagrams  No.  7  and  8,  on  the 


*  The  recent  experiments  of  Professor  Tyndall  reveal  the- 
astounding  fact,  that  the  power  of  aqueous  vapor,  at  the 
pressure  of  the  atmosphere,  to  absorb  heat,  is  6,000  timea 
greater  than  that  of  dry  air. 


58  RICHARDS*    STEAM-ENGINE   INDICATOR. 

•contrary,  being  taken  at  the  Great  Exhibition  of 
1862,  where  the  steam  was  charged  with  moisture 
In  an  excessive  degree,  show  a  great  amount  of 
re-evaporation  to  have  taken  place,  as  the  pressure 
fell  in  the  cylinder. 

The  best  means  at  present  known  for  diminish- 
ing the  loss  from  this  cause  is,  to  dry  the  steam  by 
moderate  superheating,  perhaps  sufficient  to  affect 
-the  thermometer  but  very  slightly,  since  every  atom 
of  moisture  must  change  its  state  to  steam  before 
ihe  temperature  can  rise  above  that  due  to  the 
pressure.  The  height  of  the  terminal  pressure,  as 
^shown  by  the  Indicator,  above  that  which  the  law 
•of  Mariotte  and  the  law  of  contraction  of  gases  by 
-cooling  call  for,  affords  some  indication  of  the  loss 
from  this  cause.  If  the  curve  drawn  could  agree 
with  the  requirements  of  these  laws,  there  would 
&e  demonstrably  no  loss  at  all ;  but  this  is  not  at- 
tainable. Indeed,  the  higher  temperature  of  the 
.cylinder  would  probably  affect  sensibly  the  fall  of 
pressure,  even  if  the  steam  was  perfectly  anhydrous. 
It  is  obvious,  that  the  percentage  of  loss  will  be 
•diminished,  other  circumstances  being  the  same,  in 
proportion  as  the  speed  of  piston  is  increased,  the 
actual  loss  continuing  the  same,  but  the  power  ex- 
erted becoming  greater.  Whether  the  employment 
of  two  cylinders  enables  this  loss  to  be  avoided  to 
a  greater  extent  than  it  can  be  in  a  single  cylinder, 
must  at  present  be  regarded  as  an  open  question, 
3* 


RICHARDS     STEAM-ENGINE   INDICATOR.  59 

and  is  one  the  discussion  of  which  is  foreign  to  the 
purpose  of  this  work. 

To  expand  steara  properly,  it  is  essential  that  it 
be  cut  off  instantaneously — that  is,  that  the  port 
shall  be  closed  so  quickly,  that  the  pressure  shall 
not  fall  in  the  cylinder,  from  the  advance  of  the 
piston  during  the  operation  of  closing.  This  Indi- 
cator enables  us  to  pronounce  unerringly  upon  the 
value  of  every  means  which  is  employed  to  effect 
this  object. 

Diagram  No.  6  shows  unquestionably  the  closest 
approximation  to  this  requirement.  It  was  taken 
from  an  engine  in  the  city  of  New  York,  of  the  cel- 
ebrated style  known  as  the  Corliss  Engine,  which 
is  extensively  used  in  the  eastern  part  of  the  Uni- 
ted States  for  stationary  purposes.  The  speed  of 
piston  of  this  engine  was  420  feet  per  minute. 

Diagrams  9  and  13  show  the  cut-off  made  by  the 
Sickels  valve-gear,  also  in  extensive  use  in  the 
United  States,  especially  on  boats  and  vessels.  No» 
9  was  taken  from  a  non-condensing  stationary  en- 
gine, making  30  revolutions  per  minute,  and  No. 
13  from  the  engines  of  a  steamship  at  16  revolu- 
tions per  minute.  It  is  hardly  necessary  to  add 
that  these  were  not  taken  with  the  Eichards  Indi- 
cator. The  theoretical  expansion  curves  cannot 
be  drawn  on  either  of  these  diagrams,  because  the- 
amount  of  waste  room,  which  is  considerable,  from 
the  nature  of  the  valves  employed,  is  not  known. 


<<50  RICHARDS   STEAM-ENGINE  INDICATOR. 

The  speed  of  piston  in  each  was  about  300  feet  per 
minute. 

Diagrams  Nos.  7  and  8  were  taken  from  the  Al- 
len Engine  at  the  Great  Exhibition  of  1862,  at  a 
rspeed  of  piston  of  600  feet  per  minute.  The  pres- 
sure fell  somewhat  at  this  great  speed,  as  the  clos- 
ing movement  of  the  valve  was  being  completed, 
-giving  a  rounded  corner.  In  Diagram  No.  7  we 
iind  the  expansion  curve  changed  to  a  waving  line. 
The  pressure  of  steam  was  removed  from  the  pis- 
^on  of  the  Indicator  with  such  extreme  suddenness 
•that  the  reaction  of  the  spring  was  necessarily  vio- 
lent; but  the  rounded,  flowing  nature  of  the  oscil- 
lations show  the  action  of  the  instrument  to  have 
"been  frictionless,  and  these  gradually  subside  into 
~the  correct  curve,  which  the  mean  of  the  oscillations 
gives  throughout,  as  shown.  Diagram  No.  10, 
-from  the  engines  of  a  steamship,  shows  very  su- 
perior action  of  the  cut-off  gear. 

The  vice  which  is  the  opposite  of  this  excel- 
lence is  technically  termed  wiredrawing,  and  con- 
sists in  a  gradual  fall  of  pressure  in  the  cylinder, 
"while  the  port  is  being  closed.  It  is  illustrated  in 
-various  degrees  in  several  of  these  diagrams,  and  is 
41  source  of  serious  loss.  The  object  of  cutting  off 
is,  to  obtain  the  greatest  mean  pressure  with  the 
lowest  terminal  pressure,  and  it  is  clear  that  the 
sharper  the  cut-off  the  more  completely  this  object 
is  attained.  For  example,  in  diagram  No.  1,  the 
•fiteam  expands  to  a  pressure  of  17  Ibs.  at  the  point 


RICHARDS'  STEAM-ENGINE  INDICATOR.  61 

of  release,  and  a  mean  pressure  of  21.28  Ibs.  is 
exerted  during  the  stroke  ;  had  it  been  cut  off 
sharply  at  the  point  c,  it  would  have  expanded  to  a 
pressure  of  9  Ibs.  at  the  point  of  release,  describing 
the  curve  c  g,  and  would  have  exerted  a  mean  pres- 
sure of  15.87  Ibs.  But  21.28  :  15.87  : :  17  :  12.67. 
The  gain  of  steam  from  cutting  off  sharply  would 
be  then  12.67  -  9=3.67  Ibs.,  or  29  per  cent.  But 
this  is  by  no  means  the  full  amount  of  the  gain,  for 
so  much  less  steam  being  to  condense,  1  Ib.  better 
vacuum  at  least  would  have  been  formed,  and  the 
boilers  would  easily  have  maintained  a  pressure  5 
Ibs.  higher,  with  much  more  moderated  firing ;  so 
that  the  full  mean  pressure  of  21.28  Ibs.  would  have 
been  obtained  by  cutting  off  at  the  point  c,  and 
expanding  to  a  terminal  pressure  of  10.5  Ibs.,  a  gain 
of  §J5  Ibs.,  or  38  per  cent.,  and  improvements  equal 
to  this  have  by  this  single  means  been  often  real- 
ized in  practice.  The  slide-valve  in  its  best  form 
wiredraws  the  steam  considerably,  unless  a  great 
travel  is  given  to  it;  the  vicious  practice  of  making 
the  end  V-shaped  of  course  raises  the  loss  from  this 
cause  to  the  very  highest  point. 

Diagram  No.  14  shows  the  action  of  a  single 
slide-valve  with  a  serrated  end,  expressly  contrived 
to  wiredraw  the  steam  as  much  more  than  it  can  be 
with  the  ordinary  slide  as  possible. 

The  mean  pressure  for  different  points  of  cut-ofij 
may  be  found  by 


62  RICHARDS'  STEAM-ENGINE  INDICATOR. 


HYPERBOLICAL    LOGARITHMS. 

RULE. — Divide  the  length  of  the  stroke  by  the 
length  of  the  space  into  which  the  steam  is  admit- 
ted; find  in  Table  No.  IV.  the  logarithm  of  the 
number  nearest  to  the  quotient,  to  which  add  1,  the 
sum  is  the  ratio  of  the  gain;  then  find  the  terminal 
pressure,  by  dividing  the  initial  pressure  by  the 
proportion  of  the  stroke  during  which  the  steam  is 
admitted,  and  multiply  it  by  the  logarithm  -J-  1, 
found  as  above;  the  product  will  be  the  mean  pres- 
sure through  the  stroke. 

EXAMPLE. — Suppose  the  length  of  the  stroke  to 
be  48  inches,  the  initial  pressure  to  be  40  Ibs.  per 
square  inch,  and  the  steam  to  be  cut  off  at  12  inches 
of  the  stroke,  what  will  be  the  mean  pressure  ? 

48^12=4.    Hyp.  log.  of  4=1.38629+1=2.38629. 

Then,  40  -^  4  =  10  X  2.38629  =  23.8629  Ibs.,  the 
mean  pressure  required. 

To  find  the  initial  pressure,  add  the  atmospheric 
pressure,  15  Ibs.,  to  the  pressure  shown  by  the  gauge, 
and  from  the  mean  pressure  found  as  above  sub- 
tract the  counter-pressure,  to  ascertain  the  actual 
mean  pressure  exerted.  Thus,  in  the  above  case, 
the  gauge  is  supposed  to  show  a  pressure  of  25  Ibs. 
only,  and  if  the  calculation  is  being  made  for  a  con- 
densing engine,  the  estimated  loss  from  imperfect 
vacuum  must  be  subtracted,  and  if  for  a  non-con- 
densing engine,  the  pressure  of  the  atmosphere, 
and  also  any  estimated  counter-pressure  above  that, 


63 

must  be  subtracted  from  23.8629,  the  mean  pressure 
found  by  the  calculation. 

The  editor  remarks  that  the  above  rule  requires 
a  little  qualification,  to  be  considered  correct.  If 
the  diagram  shows  the  cut-off  at  J  of  the  stroke,  it 
does  not  follow  that  |  is  the  grade  of  expansion,  be- 
cause the  clearance  has  not  been  taken  into  account. 

EXAMPLE. — Suppose  the  length  of  the  stroke  to 
be  36";  initial  pressure,  to  be  50  Ibs.  per  square 
inch,  and  the  steam  to  be  cut  off  at  9"  of  the  stroke, 
what  will  be  the  average  pressure  ? 

36-^-9=4.  Hyp.  Log.  of  4=1.38629+1=2.38629. 
Then  50-1-4=12.5X2.38=29.75,  mean  pressure 
required.  This  is  correct  without  taking  the  clear- 
ance into  account. 

Now,  let  us  see  what  the  result  is,  when  we  add 
the  clearance  in  the  following  examples;  which  is 
an  actual  case  occuring  in  my  practice  during  the 
week  in  which  this  was  written. 

Engine  36"  strokeXl^"  diameter,  cutting  off  at  J 
(9") ;  initial  pressure  50  Ibs.  to  the  square  inch  ; 
revolutions  per  minute,  80  ;  clearance  equal  to  -fa 
of  the  cubical  contents  of  the  part  of  the  cylinder 
occupied  by  the  piston  stroke  ;  or  what  is  the  same 
thing,  -fa  of  the  stroke,  which  is  equal  to  1.64", 
added  to  9",  the  point  of  cut-off,  is  10.64"  ;  which 
being  divided  by  the  length  of  the  stroke,  gives  us 
as  a  quotient  3.39,  with  a  mean  pressure  of  32.59 
Us.,  as  calculated  by  the  above  rule,  adding  the 
clearance. 


64  RICHARDS*    STEAM-ENGINE  INDICATOR. 

Computing  it  by  the  same  rule,  without  taking 
account  of  the  clearance,  the  average  pressure  is 
29.75  Ibs.  The  result  stands  thus,  computing  with 

the  clearance  added 73.00  H.  P. 

Without  the  clearance 66.64  "    " 


Difference 6.36 

In  using    Table  No.  V.,  the   clearance  must  be 
added  to  get  the  correct  mean  pressure. 


IV.  THE  EXHAUST  LINE  AND  THE  LINE  OF  COUNTER- 


may  properly  be  considered  together.  It  is,  of 
course,  desirable  that  the  pressure  of  the  steam  be 
got  rid  of  as  completely  as  possible  before  the 
piston  commences  its  return  stroke.  This  is 
accomplished  in  a  non-condensing  engine  by  having 
the  exhaust  port  and  passages  sufficiently  large,  and 
opening  the  port  a  sufficient  time  before  the  termi- 
nation of  the  stroke,  according  to  the  density  of  the 
steam  to  be  released  and  the  velocity  of  the  piston. 
The  passages  and  pipes  communicating  with  the 
atmosphere  should  be  at  least  50  per  cent,  larger 
than  the  ports,  and  as  free  from  angles  as  possible. 

These  requirements  apply  to  condensing  engines 
even  more  strongly,  and  in  addition  the  condenser 
and  air-pump  must  be  able  to  maintain  a  proper 
'  vacuum. 

Diagrams  Nos.  6  and  9  show  no  back-pressure  at 


RICHARDS'  STEAM-ENGINE  INDICATOR.  65 

all  above  the  atmosphere  ;  diagrams  Nos.  7  and  8 
show  a  trifling  back-pressure,  attributable  to  the 
number  of  angles  in  the  pipe  necessary  for  connect- 
ing with  the  exhaust  main  at  the  Exhibition. 

Diagram  No.  10  exhibits  remarkable  exhaust  and 
counter-pressure  lines,  obtained  by  a  surface  con- 
denser, while  No.  13  shows  a  great  loss  of  power 
from  imperfect  vacuum,  which  was  very  partial  at 
the  best,  and  that  only  gradually  obtained. 


V.    THE   COMPRESSION-LINE. 

This  line,  when  it  exists,  is  formed  by  the  closing 
of  the  exhaust  port  at  some  point  before  the  termi- 
nation of  the  stroke,  when  the  advancing  piston 
compresses  the  confined  steam  to  a  density  propor- 
tioned to  the  decrease  of  volume.  This  is  illustrated 
in  various  degrees  in  several  of  the  diagrams  here 
shown.  This  action  occasions  a  loss  of  power,  but 
not  much  waste  of  stream,  because  the  confined 
steam  reacts  on  the  return  stroke  with  a  force  equal 
to  that  expended  to  compress  it.  It  is  useful  on 
engines  running  at  high  velocities,  by  taking  up 
gradually  all  looseness  of  the  joints,  and  prevent- 
ing the  entire  force  of  the  steam  from  striking 
suddenly  on  the  piston.  Indeed,  so  important  is 
the  compression  in  preventing  shocks  on  the  centres 
in  engines  of  this  class,  that  probably  locomotives 
could  not  be  safely  run  without  it.  At  the  same 
time,  the  nature  of  the  valve  and  gear  employed  on 


66  BICHAKDS*    STEAM-ENGINE   INDICATOR. 

this  class  of  engines  is  such,  that  when  cutting  off 
very  early  the  compression  becomes  excessive, 
involving  an  increase  in  the  counter-pressure  as 
the  piston  approaches  the  centre,  which  is  quite 
unnecessary  for  any  useful  purpose,  as  is  illustrated 
especially  in  diagram  No.  4.  At  any  ordinary 
number  of  revolutions  per  minute  made  by  station- 
ary or  marine  engines,  the  compression  is  not 
required,  but  in  a  moderate  degree  is  never, 
perhaps,  objectional.* 


*  We  do  not  think  our  author  gives  sufficient  prominence 
to  the  advantages  of  compression ;  all  engines  require  it,  to  a 
greater  or  less  degree,  depending,  of  course,  on  the  speed  and 
action  of  the  valves.  Our  practice  is,  when  we  can  control 
the  exhaust  valves,  to  compress  from  one-half  to  the  whole 
initial  pressure.  A  great  point  gained  by  compression  is,  to 
take  up  and  store  away,  to  assist  on  the  return  stroke  the 
momentum  of  the  piston  and  its  connections  with  the  crank  ; 
also,  to  fill  the  ports,  passage-ways  and  clearance  with  exhaust 
steam,  that  we  may  not  have  to  call  on  the  boiler  for  it.  It  is 
certainly  easier  on  the  machine  to  take  up  slack  motion  of  the 
joints  thus  gradually,  than  to  take  high  steam  on  before 
reaching  the  centre.  It  is  true,  we  reduce  the  capacity  of  the 
cylinder,  but  lose  no  steam ;  on  the  contrary,  save  the  momen- 
tum of  the  reciprocating  parts,  by  compressing  a  portion  of 
the  exhaust  steam.  When  the  slide-valve  is  used,  it  serves 
to  partially  balance  it  during  the  compression,  thereby  reliev- 
ing it  from  friction  and  wear  ;  a  very  important  consideration, 
particularly  on  large  valves.  We  prefer  also  to  give  very  little 
or  no  steam  lead;  let  the  centre  be  past  or  nearly  so,  and  the 
piston  on  its  way  back,  before  the  steam  is  admitted. 

Many  a  crank  and  its  connections  have  been  broken,  brasses 


RICHARDS'  STEAM-ENGINE  INDICATOR.  C7 

Diagram  No.  12,  not  taken  by  the  Richards  Indi-. 
cator,  shows  the  usual  form  of  diagram  made  by  the 
double  opening  slide-valves  now  in  general  use  on 
marine  engines,  with  an  independent  cut-off  valve. 
It  will  be  observed,  that  the  steam  line  is  well  main- 
tained until  the  cut-off  valve  commences  to  close, 
when  the  pressure  falls  in  an  increasing  ratio,  prob- 
ably to  about  the  pressure  indicated  by  the  dots  at 
the  exact  distance  of  closing. 

In  the  preparation  of  this  paper,  and  in  the 
selection  of  diagrams  for  its  illustration,  its  object 
has  been  carefully  kept  in  view,  and  while  it  is 
hoped  that  nothing  has  been  omitted  which  is 
essential  to  guide  one  before  unacquainted  with  the 
Indicator  in  learning  how  to  employ  it  correctly 
and  intelligently,  care  has  been  taken  to  introduce 
only  those  topics,  and  to  consider  these,  only  to 
that  extent  which  seemed  to  be  necessary  for  this 
purpose. 

THE  THEOEETIC  CURVE  AND  ITS  USES. 

When  we  wish  to  know  the  condition  of  the 
internal  working  of  an  engine  from  a  diagram  we 
have  taken  from  it,  we  make  a  perfect  diagram 

worn  out;  heating,  straining,  and  thnmping,  with  all  their 
concomitant  evils,  are  daily  caused  by  excessive  steam  lead  ; 
while,  by  compressing,  the  piston  meets  the  thin  elastic  vapor 
remaining  in  the  cylinder  without  a  shock.  It  is  technically 
called  "  cushioning,"  a  most  appropriate  term. 


68  BICHARDS     STEAM-ENGINE   INDICATOR. 

around  it  so  we  may  compare  the  one  with  the 
other. 

To  do  this  :  First,  we  ascertain  the  clearance 
between  the  piston  and  cover,  also  the  areas  of  the 
ports  and  passage-ways  clear  back  to  the  valves, 
both  steam  and  exhaust,  if  they  be  separate. 

This  we  reduce  to  cubic  inches  ;  we  then  get  the 
cubic  inches  of  the  cylinder,  or  that  part  of  it  occu- 
pied by  the  stroke.  Suppose  the  cylinder  to  be  14" 
diameter,  and  36"  stroke,  it  will  contain  5541.48 
cubic  inches.  Now,  then,  suppose  our  clearance  is 
206.44  cubic  inches ;  this  being  divided  into  the 
contents  of  the  stroke  part  of  the  cylinder,  5541.48, 
gives  us  27,  or  is  ^  part  of  it.  We  then  add  to  the 
steam  end  of  our  diagram  ^  part  of  its  length. 
We  then  draw  the  line  of  perfect  vacuum,  whether 
it  is  a  condensing  engine  or  not.  Then  we  space 
the  whole  in  ten  or  more  equal  divisions,  and  erect 
lines  (ordinates)  on  these  spaces  at  right  angles  to 
our  vacuum  line,  as  shown  in  diagram  No.  0. 

We  will  suppose  we  have  100  Ibs.  from  A  to  B, 
Diagram  No.  0,  measuring  from  the  line  A  E,  and 
we  cut  off  at  0,  which  is  ^  or  ^;  by  the  law  of  expan- 
sion we  should  find  (having  expanded  the  steam  £) 
the  terminal  pressure  to  be  -J-  of  the  pressure  at  C, 
the  steam  having  expanded,  $  of  the  whole  diagram. 
To  find  the  point  where  the  true  curve  should  bisect 
the  ordinates,  we  have  numbered  them  from  one  to 
ten.  We  find  the  steam  is  cut  off  at  2,  the  next 
ordinate  is  3,  this  being  |  the  length  of  2  ;  hence, 


KICHAKDS'  STEAM-ENGINE   INDICATOR.  69 

we  use  2  for  the  numerator  and  3  for  the  denom- 
inator, and  so  on  to  the  end,  using  for  the  numera- 
tor the  number  of  the  ordinate  where  the  steam  is 
cut  off,  and  for  a  denominator  the  number  of  the 
ordinate  whose  length  we  seek. 

It  often  happens  in  spacing  our  diagrams  that 
we  can't  find  a  space  that  will  come  right  in  both 
divisions  of  the  diagram.  In  that  case  we  space 
the  parts  from  B  to  C  into  equal  spaces,  say  from 
J"  to  |"  each  and  then  space  the  remainder  the  same; 
if  it  should  run  over  the  termination  of  the  diagram 
it  is  of  no  importance,  as  after  the  curve  is  estab- 
lished the  measure  will  be  taken  at  the  terminal 
point.  The  practical  application  of  the  theoretic 
curve  is  this  :  If  we  find  it  below  the  curve  given 
by  the  instrument,  we  seek  for  the  cause ;  if  the 
engine  cuts  off  short,  say  at  J  or  less  of  the  stroke, 
we  may  expect  to  find  it  a  little,  say  a  pound  or 
two,  above,  at  the  last  \  or  f  of  the  stroke;  this  is 
accounted  for  by  re-evaporation  of  the  water  con- 
densed in  the  first  part  of  the  stroke.  But,  if  it 
should  run  as  it  often  does  10  or  15  pounds  above, 
we  conclude  at  once  that  the  steam  valve  leaks. 
If  we  find  the  curve  made  by  the  instrument  fall- 
ing below  the  theoretic  line,  we  are  certain  that 
either  the  piston  or  exhaust  valve  leaks,  or  may  be 
both. 

Diagram  No.  15  was  taken  from  an  engine 
24"  X  48",  making  50  revolutions  per  minute.  The 
steam  valves  are  of  the  class  known  as  balanced 


70  RICHARDS'    STEAM-ENGINE    INDICATOR. 

poppet ;  the  exhaust  valves  plain  slide ;  point,  of 
cut-off  adjusted  by  the  action  of  the  governor. 
Boiler  pressure  48  Ibs.,  steam  pipe  6"  diameter  by 
150'  in  length,  the  exhaust  pipe  1"  diameter  by  175' 
long,  scale  of  the  instrument  30  Ibs.  to  the  inch; 
work  being  done,  driving  two  trains  of  rolls,  one 
of  20",  the  other  of  16"  diameter,  with  the  concom- 
itant and  other  machinery. 

It  will  be  observed  that  the  pressure  in  the  cylin- 
der fell  off  some .  10  Ibs.  from  the  initial  in  the 
boiler,  which  is  easily  accounted  for  by  the  great 
length  of  the  steam  pipe.  The  2  Ibs.  back  pressure 
may  be  accounted  for  by  the  excessive  length  of  the 
exhaust  pipe  ;  these  defects  are  no  fault  of  the 
engine. 

The  card  is  a  very  excellent  one;  we  rarely  see  its 
equal — no  superiors,  unless  from  an  engine  whose 
cylinder  is  jacketed  with  high  steam.  It  will  be 
seen  that  the  lines  given  by  the  instrument  vary 
but  little  from  theoretic  curve.  The  engine  was 
constructed  by  Messrs.  Woodruff  &  Beach,  under 
Mr.  Wm.  Wright's  patent. 

Diagram  No.  16  was  taken  from  the  top  of  the 
cylinder  of  the  steamer  Newport;  it  will  be  recog- 
nized by  the  engineer  as  very  good.  The  steam 
pressure  on  the  boiler  was  by  the  gauge  22  Ibs., 
vacuum  per  gauge  26".  It  will  be  seen  that  the 
diagram  shows  20.5  Ibs.  The  terminal  point  is  sup- 
posed to  be  as  should  be;  yet,  not  having  the  data 
to  calculate  the  area  of  the  clearance,  passage-ways, 


RICHARDS'  STEAM-ENGINE  INDICATOR.  7^ 

etc.,  we  cannot  ascertain  where  the  terminal  point 
should  be,  exactly. 

If  the  exhaust  had  opened  a  little  earlier,  it 
would  have  improved  the  vacuum  at  its  commence- 
ment. 

Diagram  No.  17  is  from  an  engine  24"  diameter 
X48"  stroke,  60  revolutions  per  minute,  Babcock 
&  Wilcox  patent ;  cylinder  jacketed  with  steam 
from  the  boiler.  The  clearance  is  ^  of  the  stroke, 
boiler  pressure  72  Ibs.  to  square  inch,  scale  40"=1". 

This  engine  is  in  the  flouring  mills  of  Messrs. 
Chapin,  Miles  &  Co.,  Milwaukie. 

The  work  being  done  when  the  diagrams  were 
taken  was  driving  4  runs  of  4'  6"  stones,  and  2  runs 
of  4' ;  180  revolutions  per  minute,  with  all  the 
required  flouring  machinery  as  used  in  such  mills. 

We  give  this  data,  that  any  one  who  wishes  can 
make  the  theoretical  curve;  it  will  be  found  almost 
perfect. 

The  expansion  line,  it  will  be  noticed,  is  some- 
what waved,  which  is  incident  to  the  high  speed, 
high  pressure,  and  early  opening  of  the  valves. 

The  terminal  point  of  the  expansion  line  will 
be  found  about  3  Ibs.  above  the  true  line,  caused 
by  evaporation  of  water  that  went  over  with  the 
steam. 

Another  and  unusual  point  is  the  very  near 
approach  of  the  pressure  in  the  cylinder  to  that  in 
the  boiler,  being  but  2J  Ibs.  less.  When  we  take 
into  consideration  the  speed  of  the  piston,  480'  per 


72  RICHARDS'  STEAM-ENGINE  INDICATOR. 

minute,   the  result  is   extraordinary  and  seldom 
attained. 

Diagram  No.  18 ;  these  cards  were  taken  from 
a  Wilcox  air  engine,  and  beautifully  illustrate  the 
delicate  action  of  the  Richards  Indicator.  Fig.  1 
is  from  the  working  cylinder ;  the  receiving  line 
shows  the  induction  valve  to  be  slightly  behind 
time;  the  pressure  gradually  reduces  the  first  of  the 
stroke,  as  the  reservoir  containing  the  compressed 
air  is  small,  but  as  soon  as  the  pump  begins  to 
deliver  into  the  reservoir,  the  pressure  continues 
uniform  till  the  induction  valve  closes  near  the  end 
of  the  stroke;  the  exhaust  is  free,  and  there  is  a 
slight  compression  at  the  end  of  the  return  stroke. 

Fig.  2  is  from  the  pump,  whicb  is  §  of  the  capa- 
city of  the  working  cylinder,  and  shows  the  gradual 
increase  of  pressure  as  the  piston  descends  and 
compresses  the  air;  the  curves  or  waves  at  the 
point  of  greater  pressure  show  the  power  required 
to  open  the  eduction  valve;  the  pressure  then  con- 
tinues uniform  till  the  induction  to  the  working 
cylinder  closes,  when  the  pressure  runs  up  ;  at  the 
commencement  of  the  return  stroke  of  the  pump 
piston,  the  pencil  mark  inclines  back,  showing  the 
time  required  for  the  closing  of  the  eduction  valve, 
and  the  wave  below  the  atmospheric  shows  the 
time  and  power  for  opening  the  induction  valve. 

The  working  cylinder  is  16"  X  16"  stroke,  and 
makes  70  revolutions  per  minute,  scale  12  Ibs.  to 
one  inch. 


RICHARDS'  STEAM-ENGINE  INDICATOR.  73 

The  pump,  Fig.  2,  is  §  the  capacity  of  the  work- 
ing cylinder,  Fig.  1;  hence,  we  measure  the  average 
pressure  of  the  two  diagrams,  each  separately. 
Suppose  the  working  cylinder  to  show  an  average 
of  10  Ibs.  to  the  square  inch,  and  the  pump  diagram 
to  show  9  Ibs.  to  the  square  inch.  The  pump  being 
f  of  the  capacity  of  the  working  cylinder,  we  divide 
the  mean  pressure,  which  we  have  assumed  as  9  Ibs., 
by  3,  the  quotient  is  3,  this  added  to  10  is  13;  3  sub- 
tracted from  9  leaves  6,  which  subtracted  from  13 
leaves  7  Ibs.  effective  pressure  per  square  inch  on 
the  piston. 

Our  author  concludes  the  work  with  a  graphic 
account  of  "  A  Bide  on  the  Buffer  Beam"  on  the 
Great  Eastern  Railway,  making  the  trip  from  Lon- 
don to  Yarmouth  (England)  in  company  with  Mr. 
Zerah  Colburn,  for  the  purpose  of  taking  diagrams 
from  the  engines,  in  which  they  were  eminently 
successful;  which  the  compiler  of  this,  owing  to  the 
prescribed  limits  of  this  work,  reluctantly  feels 
compelled  to  omit,  and  substitute  an  account  of  a 
similar,  though  shorter,  trip — from  Wilmington, 
Del.,  to  Philadelphia,  on  the  Philadelphia,  "Wil- 
mington and  Baltimore  E.  E.  Through  the  kind- 
ness of  Mr.  G.  W.  Perry,  master  of  machinery  of 
that  road,  Locomotive  No.  50,  a  first-class  express 
engine  built  by  "  the  Taunton  Locomotive  WTorks" 
— cylinders  16"  diameter  by  24"  stroke,  four  driving 
wheels  5'  6"  diameter,  making  305.46  revolutions  to 
fche  mile — was  placed  at  the  disposal  of  the  writer, 


74  RICHARDS'  STEAM-ENGINE  INDICATOR. 

and  fitted  for  the  occasion  under  his  directions  by 
Mr.  S.  A.  Hodgman,  the  able  and  efficient  master 
mechanic  of  the  shops.  The  engine  is  outside  con- 
nected. The  diagrams  were  taken  from  the  for- 
ward end  of  each  cylinder. — Short  J ' '  pipes  were 
screwed  into  the  top  parts  of  the  cylinder  covers, 
with  elbows  f  "  internal  diameter  pointing  upwards, 
to  which  the  Indicators  were  attached.  An  iron 
rail  was  secured  to  the  signal  flag-stands  on  the 
narrow  platform  in  front;  a  packing-box  some  9" 
high  served  as  a  seat  for  each  operator,  with  his 
back  to  the  wind,  and  the  Indicator  between  his 
knees. 

The  method  employed  for  giving  motion  to  the 
papers  was  very  simple.  A  plank  on  each  side  of 
the  boiler,  running  from  the  cab  to  the  platform, 
about  3 '  above  the  cross-head,  and  directly  over  it, 
which  was  used  for  the  purpose  of  going  forward 
to  oil,  etc.,  was  morticed  through  in  the  proper 
place,  and  a  bracket  with  a  hole  through  it  to 
secure  the  arm  to,  was  bolted  to  the  plank  beside 
the  mortice.  A  stud  with  a  nut  on  it  was  fastened 
to  the  bracket,  pointing  outwards  horizontally.  A 
light  arm  swung  from  this  stud  and  received  a 
vibratory  motion  from  another  stud  screwed  into 
the  side  of  the  cross-head,  working  in  a  well-fitted 
slot  in  the  lower  end  of  the  arm.  A  button-headed 
pin  was  inserted  in  this  arm  at  about  7"  below  the 
point  of  suspension,  and  to  this  was  attached  the 
cord  leading  directly  to  the  Indicator,  giving  to  the 
3 


RICHARDS'  STEAM-ENGINE  INDCCATOR.  75 

paper  a  motion  of  4J".  Great  care  was  taken  to 
set  the  arm,  so  that  when  the  engine  was  on  the 
half-stroke  and  the  cord  attached  to  the  instru- 
ment, it  might  be  at  right  angles  with  the  arm. 
The  cord  had  a  hook  about  2"  long,  with  a  bend 
about  1J"  diameter,  with  a  corresponding  one  on 
the  instrument  cord,  which  made  it  easy  to  attach 
under  any  speed.  The  hook  on  the  cord  was 
secured  by  two  other  cords  to  keep  it  in  position, 
allowing  it  to  move  back  and  forth,  but  not  to  fall 
when  disengaged,  where  it  could  not  be  readily 
seized. 

It  was  arranged  with  the  engineer  that  he  should 
run  at  all  times  with  the  throttle-valve  fully  open, 
governing  the  speed  entirely  by  changing  the  point 
of  cut-off.  Everything  being  ready,  Mr.  Hodgman, 
the  master  mechanic  of  the  shops,  and  myself,  pre- 
pared to  mount  the  platform.  It  being  the  month 
of  November,  and  not  being  very  warm,  an  extra 
overcoat  was  put  on;  a  pair  of  woollen  gloves, 
fingers  amputated  at  the  second  joint,  leaving 
enough  of  the  finger  bare  to  manipulate  the  instru- 
ments, were  found  to  work  well. 

Our  first  essay  was  with  the  engine  and  tender 
alone,  to  see  that  all  was  right.  We  took  several 
diagrams,  both  on  the  forward  and  backward  mo- 
tions. We  found  the  valves  remarkably  well  set. 

Diagram  No.  19  is  one  of  a  pair  that  were  taken 
when  running  about  20  miles  per  hour;  working 
the  steam  full  stroke,  both  backwards  and  forwards, 


76  BICHAKDS*   STEAM-ENGINE   INDICATOR. 

shows  how  nearly  the  two  actions  correspond.  Its 
mate  from  the  right-hand  cylinder  is  a  perfect  fac- 
simile of  the  one  we  engrave.  In  taking  these  cards, 
the  throttle  was  quite  open.  Pressure  of  steam  not 
noted.  The  scale  of  the  instrument  40  to  the  inch. 
During  these  preliminary  experiments,  an  unfortu- 
nate accident  happened  to  one  of  the  instruments 
by  breaking  a  spring.  Not  having  an  extra  40 
spring,  we  substituted  a  30  spring  in  each  instru- 
ment, and  that  we  might  get  sufficient  range,  we 
put  washers  between  the  end  of  the  spring  and  the 
piston,  of  sufficient  thickness  to  carry  the  piston 
down  to  the  vacuum  line,  thereby  giving  us  a  scope 
of  15  Ibs.  more,  and  sufficient  to  answer  the  require- 
ments for  105  Ibs.  pressure  in  the  cylinders.  I  men- 
tion this  for  the  reason  that  should  the  young 
engineer  meet  with  a  similar  mishap,  he  may  be 
posted  on  the  subject.  The  delay  caused  by  this 
mishap  prevented  us  from  carrying  out  a  programme 
we  had  made  previously.  At  4  p.  M.  the  express 
train  arrived  from  Baltimore,  which  it  had  been 
arranged  for  us  to  take  to  Philadelphia.  We  took 
diagrams  at  speeds  varying  from  30  to  60  or  more 
miles  per  hour,  with  great  facility,  at  full  stroke,  and 
cutting  off  at  various  points.  In  consequence  of 
our  weak  springs,  our  experiments  were  limited  in 
pressure  to  105  Ibs.,  hence  we  could  not  maintain 
our  speed  when  cutting  off  short. 

Diagram  No.  20,  scale  30  to  the  inch  from  the 
right  hand  cylinder,  cutting  off  at  about  one  fourth 


EICHAEDS 


^-'1  -:R" 

STEAM-ENGINE   INDICATOK. 


stroke,  was  taken  at  60  miles  per  hour,  piston  making 
1,222  feet  per  minute,  305.46  revolutions.  Notwith- 
standing this  extraordinary  speed  of  piston,  the 
lines  are  all  well  denned,  showing  distinctly  the 
points  of  cut-off  and  release.  A  remarkable  point 
in  the  diagram  is,  that  though  the  pencil  passed 
over  it  certainly  twice  or  more,  the  lines  are 
very  near  to  each  other,  showing  that  even  under 
this  unprecedented  speed  of  piston  the  instrument 
was  uniform  and  reliable  in  its  action.  This  is  not 
a  selected  diagram  ;  all  others  taken  on  the  trip 
show  the  same  characteristics, 

Diagram  No.  21,  same  scale,  from  the  left-hand 
cylinder,  cutting  off  one  notch  shorter,  with  a  higher 
pressure  of  steam,  taken  next  after  the  foregoing, 
exhibits  the  same  general  features,  though  taken 
under  a  higher  speed. 

Diagram  No.  22,  same  scale,  was  next  taken, 
working  full  stroke,  with,  as  will  be  seen,  throttle 
full  open  ;  the  speed  increasing  to  such  a  degree 
that  the  engineer  thought  it  prudent  to  put  on  £ 
cut-off. 

This,  as  do  all  the  other  diagrams  taken  from  the 
engine,  shows  most  marked  points  in  the  construc- 
tion and  setting  of  the  valves;  notwithstanding  the 
great  speed,  the  steam  line  is  held  uniform  to  the 
points  of  release.  The  exhaust  line  is  all  that  can 
be  desired.  The  back  pressure  is  merely  nominal, 
the  exhaust  nozzles  being  4  J"  each.  In  getting  the 
diagrams,  the  writer  was  ably  seconded  by  Mr. 


78  RICHARDS'  STEAM-ENGINE  INDICATOR. 

Hodgman,  who,  though  it  was  his  first  attempt  at 
taking  diagrams,  was  remarkably  efficient  and  cor- 
rect. 

We  have  spoken  of  the  accuracy  of  the  valve- 
setting.  These  valves  were  set  wholly  by  marks 
on  the  wheels,  slides,  and  valve-rods,  with  steam 
on,  and  of  course  valve-chest  covered,  which  is  the 
only  method  by  which  they  can  be  correctly  set, 
owing  to  the  expansion  of  the  parts  by  heat. 

We  would  here  refer  the  engineer  who  wishes  to 
be  well  informed  on  the  important  art  of  valve- 
setting,  to  a  very  excellent  work  on  the  slide  valve 
and  link  motion  by  Mr.  W.  S.  Auchincloss,  recently 
published  by  D.  Van  Nostrand,  23  Murray-street, 
New  York,  which  is  the  result  of  great  research  and 
practical  experience;  from  which  we  copy: 


"HOW   TO   SET   A   SLIDE   VALVE   HAVING   EQUALIZED 
EXHAUST. 

"  1.  Place  the  crank  at  the  180°  location,  mark 
on  the  cross-head  and  one  of  its  guides  opposing 
'  centre  punch  '  points, 

"  2.  Bring  the  crank  to  the  zero  and  mark  a  se- 
cond point  on  the  guide.  The  two  points  thus 
found,  measure  the  length  of  the  stroke.  Move  the 
eccentric  until  the  valve  has  the  required  lead  for 
the  forward  stroke. 

"  3.  Advance  the  crank  in  the  direction  of  the 
motion  until  the  exhaust  of  the  opposite  stroke 


RICHARDS'  STEAM-ENGINE  INDICATOR.  79 

closes  ;  scribe  a  line  across  the  guide  which  shall 
pass  through  the  point  on  the  cross-head. 

"  4.  Move  the  crank  until  the  other  exhaust  closes 
and  scribe  a  second  line  on  the  guide. 

"  5.  If  now  the  exhaust  should  close  at  equal  dis- 
tances from  the  commencement  of  each  stroke,  the 
motion  would  be  in  adjustment;  if  not,  alter  the 
length  of  the  eccentric  rod  until  the  closure  becomes 
equalized,  then  return  the  crank  to  the  zero  posi- 
tion, and  alter  the  angular  advance  of  the  eccentric 
until  the  required  lead  of  the  forward  stroke  is 
secured. 

"  The  position  of  the  valve  at  the  moment  of 
closure  may  readily  be  fixed  by  means  of  a  '  valve 
gauge '  fitting  centre  punch  points  on  the  valve 
stem  and  its  stuffing  box. 

"  The  above  process  will  serve  also  to  equalize 
the  cut-off  if  the  valve  be  proportioned  for  this 
object." 

The  trip  was  not  without  its  discomforts,  however 
successful  it  might  have  been,  being  accomplished 
on  a  November  afternoon,  with  rather  a  low  ther- 
mometer ;  with  nothing  at  our  backs  to  break  off 
the  wind,  with  low  seats  and  otherwise  constrained 
positions,  we  at  the  conclusion  of  our  trip  found 
ourselves  somewhat  cold  and  a  little  stiff.  Had  it 
been  a  summer  day,  this  source  of  discomfort  would 
not  have  been,  and  we  should  have  enjoyed  the 
excitement  of  our  trip  much. 

So  far  as  it  is  known  to  the  writer,  the  above  is 


80  RICHARDS'  STEAM-ENGINE  INDICATOR. 

the  first  successful  application  of  the  Indicator  to 
a  locomotive,  when  making  a  regular  trip  on  the 
road,  in  this  country.  It  is  quite  certain  that  there 
is  no  Indicator  known  but  the  Richards,  that  can 
be  successfully  used  for  the  purpose.  We  will  con- 
clude with  Mr.  Porter's  concluding  paragraphs  of 
his  "  Bide  on  a  Buffer-Beam  :" 

"  These  diagrams  are  taken  under  fewer  difficul- 
ties than  would  be  at  first  imagined,  if  the  weather 
is  pleasant,  and  the  proper  provision  is  made  for 
the  comfort  and  security  of  the  operators.  The 
principal  difficulty  is  from  the  wind,  which,  at  very 
high  speed,  approaches  more  nearly  to  a  hurricane 
than  anything  that  one  is  able  to  experience  in  this 
latitude  in  any  other  way,  and  the  labor  of  resist- 
ing it  becomes  quite  wearisome,  if  the  operator  is 
not  somewhat  protected  from  its  force.  No  un- 
pleasant sensation  whatever  is  produced  by  the 
rapid  motion,  the  passing  of  trains  is  scarcely  ob- 
served, and  if  no  accident  happens,  there  is  no 
danger  more  than  in  the  carriages.  Good  weather 
is  essential  to  the  satisfactory  accomplishment  of 
the  objects  of  such  an  excursion." 


RICHARDS'  STEAM-ENGINE  INDICATOR. 


81 


1  O   **  CO 


co  •<*•  "1  VO  f^OO  ON  O     >-i  CO   CO  ^J-  to  vO  t->-00  ON 


of 


•-tCOCOCNTH-^OOOOtoOro  OOO  t>.vO  vO    OO   O   CO  vO   O 

VO  to  to  to  t*«  ON    CO  vO   i-i  r^.  co  CO   ON  ^-vO  to    i-i  to  to  CO  r~^ 

roroO-^-«oroONi-iHHt^i-i  co  <O  r^  ro  «o    rovO  to  O  O 

vO  00  vo   ONOO   ro    co  O   CO  ON  ro      • 

i-i   O   >->   -3-00     rt-  i-i   O   *"   CO 

CO  vO  i-i  OQ  r-^    r-»  ON  co  <O  ro  ^ro^or^ON    co  tooo  >-•  •& 
M  i-i  co    co  <<frvo  r^ON>-«»-it-ii-ii-i    ncococoro 

vovoto^vooo   oot^  rooo  O  ONONi-iTj-r^    i-cvot-iooto 


"-I     I-H     Cl         CO  ^V 


0*100   ON^VO 
"^>-i     ON^t^^ 

t^  Q\       hH     1-4     l-l     M     HH 


OO  vo  CO  to  ^  HH     tovo   ^*  ON  CO     tovO   ^"  t^^  to    O   O  v 

co  vo  O  t>»  to    tovo  ON  ro  ON    O  CO   r}-vO  ON    >-<   ^f 
»-i   «   CO     co  •*  to  t^OO     i-i   IH   i-i   i-i   i-i     CO   CO 


^ 
O 


X 


.O'-' 

ON  O 


co  -^-  to  t^oo 


M  rj-oo     rooo 
CO   O  "^  OO  t^ 

VO   ON  r^    w   « 


•H   rj-  ON  10  fO 


roro    ONOO  ON  O   CO     >OOO  OOOO   ^1 
roo    vo>-iroroON    NNO  -*vo 
OO   ON  00  t^  1-1   1-1  vo    OO  toOO  vO   O 
OO  u->  .  .....  . 

ro  N  fO  tOOO  ro  O  OO  OO  O 
O  vO  O  M  -^-vO  OO  >-i  -^vO  ON  CO 
t^oo  i-iiHMi-it-i  NWNNCO 


NcoNr-.O 


OvoO'-' 

ONi-iO'!l' 


O   cov 

r^vo 

Or^. 


10  CO  01 
O  ON  to 
ON  tooo 


i-i   covO   ON 
CO    CO    CO    CO 


ONNNO     r^.co  ONV 
rovO  ON  ro  OO   M   r-J 
toowco     r^oo  ONV 


TJ-  N  M  CO  ro  to 
to  t^.vO  CO  10  to 
oo  vo  o  O  »ovo 


•     «     •     •  OOOOOOrooOtorococo 

i-i  ^l-OO  -^-CO     i-ii-irl-r^roO'-i   rovO  OO     O  rovO  ON  CO 

i-i  co    co  Tf  tovo  oo    11  i-i  i-i  «  w    cococococo 


TJ-ONCOTj-Tt-N  t^t-tNMO 
i-iO'-'<'jTj.r>.  OtOOvOro 
cocoOTj-toroON'-i'-r^'-i 
O  •->  oo  O  00  N  •-<  r^oo  rj-  1^ 


H«  COOO   co*-« 


co*-«     OONvO»-<OOi-iro  iOOO 

>-i  co    co  -^-  "^vo  oo    ON^»II-I>-I 


OO  rovO  vo  to  CO 
Oror^Moo 
tovo  rJ- 


ON 

o     ^coooo 
CO     COONroro>-' 


- 

o  ON 
>-'vo 
'-'  l^ 


O\  r^  i-i   O  vovO   co  >0  co 

41  ^vo  ON  ro  ON  t^.vO  r> 

•-•  rotot^  O  co  tooo  •-< 

M       M       M       M  CICOCOCOCO 


rfvO  vO   T!-  O 

to'-'OOvOto 

OO   ^J-vO  vO   ro 

O  r^  >->  O  tovo 


Tj-r^fOOOtocoOONONQ 

roONrorO'-'    vOOOvocovO 
roOt^ 


OONT}-IO>-« 


ON  »-«  1-1  w  w     COCOCOMCO 


O  >-i  CO   co  -^-  to  vo  l^OO  ONO     •-•COrO'^-tovO  t>>OO  ON 


RICHARDS'  STEAM-ENGINE  INDICATOR. 


•  t  un»I<T     ••«  N   co  "sh  vo  vO  t-^CO  ON©     •-<   N   CO  ^f  vo  VO  t^CO   ON  O 
•V"BKI      N   01   cVfTvS      NNNNCOCOCOCOCOCOCOCOCOCOTj- 


•s 


vo  wOO  vort- 
OO   t^  N   vo  vo 

VDOOVO  Cr^OO 

vo  MOO  vo  vo 

t-s.  1-1     TfOO     N 

C0^-^f*vo 


N  VO   t^  vo  O  CO  N  CO   N    N 

CO  CO  ON  M  ON  N   1-1  vovO     • 

SOMVON'OP  ONO^NVO  M 

vovo  vo  t^  r^  i-^oo 


&o72  2  M M 


CO  N   i-i   N   CO 
vnOO  OO  LO  ON 

a  a  oo  o  t^ 


LOGO   MVO"" 
O  OO   ^t-vO  VD 

w  ON  ^^-  o 


COOO  ^-  CO  N 
t<0  *OQ  N 
CO  rt  ^-  ^f  vo 


i  vo  ' 


vo   N   CO' 
CON   N   • 


COON    _ 

O   N   N   ON  co 
ONVO  ON  t^  N 


rj-  xt- vo 


co  HH     O  O  O  N  OO 
N  t^ 
OO  ONVO 

VONO     ONONI-IVOO 
VO  VD  I>»    r-.00  OO  ON  "-I 


r>.  OO   1-1 


w  t^vorj- 
O  cor^  M 

1-^-  ^f-  ^J-  10 


NOO>-i 

VOOO   N  OO   vo    ^h  ^"VO    O   vo  vo  i— '   t^  CO  ! 

vo  ON  ^J-OO    CO  CO    COOO    •«*•  ON  O    M    >->    N    i 

vo  vovO  vO  t^»    t^>.00  CO  ON  ON  •— '   *H   M   *— '   ' 


cooo  i-o  M 

HHt^i-iiN 
CO  "~>  ^"CO 


i  ON  COOO   CO    t^  N  OO   COOO     O   1-1   n   N   « 
i  vovO  vo  ts^    t^OO  OO   ON  ON    **  t— '   *^   *— '   w 


w   N   CO  lOOO 

OO  CO  ^O  O>  O 
vO   O   O   u-ir^ 


MvON 

ON  rt"  t^v 
COVO   ^ 


C4i-iOOt-< 
t--OO  VO   >->   c 


ON  T}-  O  t^-VO 
VOON  rovo  O 
COCO1^-  ^  vo 


t-^  ON  COOO  vo    Tj-  rf-vO   ON  ' 
vo  vovO  VO  t^    t->.CO  OO   ON  i 


.w   N  CO 

00  ON  >-< 

1  vow  CO 


VO  O  VO  co  M 
VOON  M  vo  O 
CO  CO  -tf"  ^  vo 


vo  vovO  VO  t^    t^OO  OO  ON  ON 


M  M  ON  ^hvO 
ONt^OQvo 
..... 
covo 


OVOCOMQ     ONOw   covO     ON 

O\  r^  covO  vo     N  t^OO  vO"     cocoONCOTj- 

ON  O  t-*  ON  t^    MO  vovO   CO    vo  covO  vO   •-> 


N  t>«  N   ONCO     ON  +*   •**•  ONVO      rj-  r}-  voOO 
lOOO   N  vo  ON    COCO   N  VO   <->    vO   >->  vO   <-> 

co  co  ^-  ^-  -^-  vo  tovo  vo  t-»  t>.oo  co  o- 


wvOOOr^co 

OJOOOOON 

... 

N  OO    TJ-  O  VO 
OO«MC» 


CO  ONVO   r}- 
i  CO  •*  ^*-  "4- 


O 

vovO  O 
vo  vovO 


ONN 
Ot^- 


voOOt^-ON 

'^Q     '     * 

NCOTt-OvO 

OO'-'CIC^ 


>-i   COVO   O  vo 
CO  "i   -^-  COCO 

vo   O  VON   6 
Tj-00    M    vo  ON 


OvO 

covovow 
ON  vo 


fO  *^  O  ON  ON  O  N  vo 
vo  N  vO  vO  ^i"  O  N  »-H 
t>.  voOO  t^.  N  CO  ON  t-i 

NvodvO  4-4-vot^N 
t^i-ivOO  voOvoOVO 
vovO  VO  r^  t^-CO  OO  ON  ON 


vo  vovO 


CO  N  1-1  vovO 
t^  vo  T}-  Tf-vO 
O  O  "H  >-<  N 


RICHARDS'  STEAM-ENGINE  INDICATOR. 


83 


vo  t>-oo  ON  O    n  N  co 
rJ-rJ-rJ-rJ-^O    ir)\f)\r> 


r>.oo  ON  O 
xo  10  W>v5 


OO   rJ-vO   COVO     to  O   O  VO  OO     toOO 

00  "">  CO  co  rj-    r>»  N  OO  to  4    vot^M 
•    H-iOO   vo    «    -    - 


CO  • 


"1VO 


OO   ONt^  OOO 
OO  M 

<§£ 


wi-ioONrO'-'vO  C\OO  tr> 
M  to  COOO  OO     rf  to  N  w>  Tj- 


NOOvOvOt^  OO  t>»vO  t^  ON  roOO 
r^fOOt^r}-  MONt^T^-M  OOOr-^io 
CO  TJ-  u->  u->\O  t~^  t^OO  ON  O  •-"  M  M  rn 


N»-ii^ONO     t>-i-'MOvOOOOO  tooO  ON 
t^OOOMfOOOOt^OOO     C^NOO  ONVO 


- 

•«*•    *-i  OO  vO   rj-  >-•     ONOO 
i\o     t^  t^OO   ON  O     O   "-• 


'-'     vr>i/->ON 


_ _        ...O  "-"   covO   <H  t-^ 

vo  C4   ONVO   CO    Ot^LOcO"-"  ONr^-vorJ-M 

CO  ^  Tj-  uo\O     t^.  t^OO   ON  O  O   <-•   N   CO  •<*• 

HHWWWM         M     IH     l-l     l-l     M  NNMWM 


vo  *s" 

•-I  O  ON( 

vovO  vO 

«  W  N  N  M 


o  OO  vO  >-o  tr> 
xOi-iOOiON 
r«->  Tf  rt  xovO 


^-oo  N  O 
vO^l-rO'-' 
»-'Mroi<4 


r-^vo  t^  o  '4' 
O  ONOO  OO  t~^ 
Ln  iOvO  t^OO 


^•vO  ^"  O  co  co  O  ^J"  to  ^"  ON  ^<  *^  OO  M 

1-1  ON  co  cooo  ONVO  OO  <O  O  ON  vovO  IN  vo 

vo  «  oVoo  06    6  4-  o\vd  to  -4-vo  oV  4-  6 

•*J-  »M   t^  -<^-  >-,     ONVO   CO  •-<   ON  t>.vocOvN   w 

co  ^"  Tt*  vovO    vo  t^»CO  ON  ON  O   *"*   N   co  ^" 


OO  t^OO  •-" 
ONOO  r^  r-»v 
Tj-  vovO  r^ 


wi-i     rot^«WOOr^ 
^  "-*    OO«J->roOOO    vO-^- 
t^.OO  ON  ON    O   •-* 


OO>-<tni-i 


COOO  u">Tj-rfvOCNTj-i-iONOOOMf^rO 


>Tj-rf 
coO 

LOVO 


O  vr>\o  10  >-i     CO  CO  O 
t^OON-^-io  >-ifO'-' 


N'-'OO     « 


ONMt^CO 
VO  •^•'-"  ON 
vO  t^OO  OO 


t^»  co  "-•     O   •""   Tt-OO   rt- 
-    t^    voco«   ONOO 
ON    O   •"•   <M   C«   co 


"^  -<t-  O   co  co    O   Tf-vO   -^O     "-"NOO 
NTJ-C^LOT}-    ONONiOt^^OOOt>»>-i 


O     '- 

ONVO 


RICHARDS     STEAM-ENGINE   INDICATOR. 


U.UIBIQ 


OO   O     10  IH  OO  r^OO 


ONVD  ON  t^  1-1 


IH   £.00   1000    viT  O    O 

*  oVvd  10 

ONO   IH 


O 

ON 


VO   N   •* 
«   ^-  cT 


ONNVO  N 
CS  VO  t^  O 
t^.00  ON  HH 
'^-TJ-TJ-IO 


vovo 
N^»r> 


MONCO  COOO  ON 


Rt^VO  t^  ON 
vo  vo  vo  vo 
ON  O  i-<  N  co 
N   COCOCOCO 


coOO  »0  co  co  voOO  N  ONVO 

i>-  t^oo  ON  o  w  N  -^t-  Br»tsi 

^J"  tovo  r^o\  OI^MCOT!- 

COCOCOCOCO  •^•Tj-Tj-Tj-^- 


VO  t 

o\  IH 
to  r^oo 


U4UIBIQ 


vovo   COOO     ONOO 
w  ON  CO  N     t^OO 


O 


CM  cococo 


Nt^^J-NN  COVO   M 

VO  vo  t^OO   ON  O   IH 

TJ-IOVO  i>-00  0   IH 

cococococo 


OO^OIHCIIH     t^OOt^.iH     COIHVO  ONOO     10  ON  O 
CM   COO   M   0     CO  COOO  00  10    l>.ioOO  r<N     COONN 


LO  "*•  ^  ^  ^t-  10  u-jvo  r^OO 
ON  O  I-"  M  CO  -^  iO\O  t^OO 
r»  cocococo  cococococo 


IOONIOCO  NM  100    *d- 

O   >->   co  10    l>.  ON  IH   covo 
ro  Tf    iovO  OO   ON  O 
Ti-io 


vO  OO  t^  co^O    vO  TJ-OO  ONOO     covO  vOCMvO     r^ioOcoCM 
voioO  IH  r^    ON  r>-  O  ON^-    LO  >-<  coin   ^-    cooO  ON  10 1-^ 

IH  00   t^>  t^OO      IH  VO   CO  O   O      IH 
^-  rf  IOVO   t^  00 

T*-  iovO  r^oo    ON 


rj-  t^.vO   O   IH 


CM  OO  t^  t^OO  iHVOCMOON  OCMVOCMONOOOOO'^-ON 

COCMCMCMCM  COCOTj-iOio  K.OO   ON  "    ^     ^-vO   ON  «   CO 

O\  O   IH   CM   CO  rj-  iovO  t^OO  ON  O   IH   CO  ^    iovO   «>•  ON  O 

WCOCOCOCO  COCOCO    OCO  CO  ^1-  ^  ^  ^     rj-  rj-  r^-  -5J-  10 


t^OO  VO 
rj-VO   COVO  ""> 


•H  CM   co  •«*•  10 


VO  t^OO  ONO     iHCM 
vOOvovot>i   t^t^ 


RICHARDS     STEAM-ENGINE   INDICATOR. 


85 


•j^ureja 


OOOOOOOQOQ    OQOQOOOOON    ON  ON  ON  ON  ON    ON  ON  ON  ON.  O 


vo  ON  ON  t^  H<     mc40Oi-ii-«OOttmoir^ON  ONVO  ON  O 
i-iioxoi-imOmi-'vOvO     1-1  m  O  COM     xovoi-i  0*  O 


r»  ON  moo  vo  m  m  •^•I^NOOV 

ON  N  VO   ON    COVO   O   rJ-OO     m  t^  N   t^  N     t^  N  OO   m 
' 


i-^oo  >-<  vo  1-1  oo 


ON  r^  N  rj-  m    ON  N  N  ON  Tfr-   vo  m  ON  N  •-"    00 


mmiOOOmOOO 


ON  N  vo  N 
im-ivOW 

ro  iov0  00 


10  t>.vO  COVO    VO   COOO 


ONOO     TfvO 
COO      fO^ 


N   1-1  N   Tj-OO  mOONON'-" 

rj-  t^  O  fOvO  Orl-t^.i-ivO 

CJ   CO  LOVO  t^  ON  O   «   CO  ^ 

lO  10  10  10  10  i-O\O  vOVO^O 


i-(T}-Tl-i-i 

fOOO     ONVO 


ONVO  CO  vO  O 


ONOO  ON  i-«  ^  O  VO  ^O  «-O«O  ON 
N  u-)00  NvnONClVOOTt-OO 
W  co  ^vO  t^»  OO  O  M  co  -^  v~) 


^OOOOO  ONMir^i-i 

C»   t^  M  OO   m  ON 

O   >-<  co  ^f  vO  t^ 

t^.t^  r^r^t^t^. 


10  »o  10  10  10 


rom   covo  O 
'-'O    i-ivoc^ 

O   -i      CO  -^-VO 


ON 


M  f>.  ONOO   ^J-    r-OO  10  ON  •-• 
OvOCOvO 


>O  10    >O  vovO  vo 


»OOO  OO 

NVO   O  ON 

MXO>-IOOOO  odo-^ovo 

VOQiOONTh    CMOOvO'-' 
10  t^OO   ON  «     W    ^l-vo   t^.  ON 


lO  rj-  O   CO  Tf    1-1  vo 
M  t^OO   'sJ-vO 


vO  M     tou-5MvOt^.ioOfONON 
I-H   OJ    OO   O  OO  1-1   O     *OVO  N   ^  H< 


>-<     Tf  00   N  VO 
>t^OO   ONt-i    M 

10   10  iovo  vo 


rh  ON  COOO   CO  OO   COOO   Tj-  O 
1OVO  OOON"-"      NTj-iOt^ON 

vovovOvo  r>-   t^t^t^t^.t>. 


o6vdv6o6i-H 

t^-  O   COVO   O 


to  to  *-i  co  »-<    ^-  cooo  oo  -r 
civdrl  o\oo  oo  O  rooo  to 

COt^r4vO'-'VONt^MOO 
voO  OO    ON  >-i      N   'T 


t*+  ONVO   ONOO     COCOONMOO 


vomm^J'fs»  N  oo  to  to  vo 

VO  ON  M  voOO  N  vo  ON  co  t^ 
•-i  N  -rf-  vovO  OO  ON  O  M  m 
»O  to  to  to  vo  vo  vovO  VO  VO 


oo  M  r^  rj-  co  co  vooo  m  ON 

HH  vO  O  to  O  vo  O  vo  H«  vO 

VOVO  OO  ON  I-H  C^  rj-  vo  f>»00 

vo  vo  vo  vo  t^  t^  t^^  c**-  r^»  t^^ 


8N 
O 


CO'-'O'-''!}'OOTt-Mi-ii-< 
tOOO  i-i  rj-  t-»  O  TfOO  N  VO 
••«  N  Tf"  vr.vo  OO  ON  O  N  CO 
vo  to  vo  vo  to  vo  vovo  vovo 


COI^-M   ONOO  OO   ON  C^   t^.  ^ 

O   Tf-  CN  COOO  COOO   T*-  ON  vo 

VOVQ   t^  ON  O  M   CO  vovo  OO 

vovovot^r^.  t^.r^t^.t>-t>« 


J,UI«IQ 


« 

OOOOOOOOOO    COOOOO 


86 


RICHARDS'  STEAM-ENGINE  INDICATOR. 


Circumferences  of  Circles,  advancing  by  lOths. 


1 

CIRCUMFERENCES. 

1 

o 

., 

.2 

•3 

•4 

•S 

6 

-7 

.8 

•9 

5 

O 

.00 

.31 

.62 

•94 

I    25 

•1-57 

1.88  2.19 

2.51 

2.82 

I 

3.14 

3-45 

3.76 

4.08 

4.39 

4.71 

5-02   5.34 

5.65 

5  96 

2    6.28 

6  59 

6.91       7.22 

7-53 

7  85 

8.16   8.48 

8.79 

9.11 

3  9.42 

9.73  10.05  10.3610.68 

10.9 

11.30 

11.62 

ii  93 

12.25 

412.56 

12.88^3.  19  13.50  13.82 

14-13 

H  45 

14.76  15.07 

15  39 

5  I5-7O 

16.02  16.33 

16.65  16.96 

17.27 

17-59 

17.90  l8.22 

18.53 

618.84 

19.1619  47 

19.7920.  10 

20.42 

20.73 

21.04 

21.36 

21.67 

721.99 

22.3022.61 

22.9323.24 

23.5623^,87 

24.1924.5024  Si 

825.13 

25  4425.7626.07 

26.3826.7027.01 

27-3327    6427.96 

928.27 

28.5828.9029.21 

29-53 

29.8430.15 

30.4730.7831.10 

1031.41 

31.7332-0432.35 

32.67 

32.9833  3033-61 

33-92 

34.24 

"34-55 

34.8735.18 

35.50 

35-81 

36.1236.44 

36.75 

37-07 

37.38 

1237.69 

38.0138.32 

38.64 

38.95 

39.27 

39.5839-8940.2i 

40.52 

1340.84 

41.1541.46 

41.78 

42.09 

42.41 

42.72 

43-0343-35 

43-66 

I443-98 
1547.12 

44.2944.61 
47-4347-75 

44.9245.23 
48.0648.38 

45.5545.86 
48.6949.00 

46.1846.49 
49.3249.63 

46.80 
49  95 

1650.26 

50.  57'  50.  89 

51.20 

5I-52 

5i  83 

52.15 

52.4652.77 

53-09 

1753  40 

53.7254.03 

54-34 

54-6054.97 

55-29 

55.6055.92 

56-23 

1856.54 

56.86,57/17 

57-49 

57.80 

58.11 

58.43 

58.74  59.O6 

59-37 

1959.69 

60.0060.31 

60  63 

60.94 

61.2661.57 

6l.8862.20 

62.51 

20  62  .  83 

63.1463.46 

63-77 

64.08 

64.4064.71 

65.0365.34 

65.65 

2165.97 

66.28 

66.60 

66.79 

67.29 

67.54 

67-85 

68.17 

68.48 

68.80 

2269.11 

69  42 

69.74 

70.05 

70  37 

70.68 

71  oo 

7L3I 

71.62 

71.9^ 

23 

72.25 

72-57 

72.88 

73-19 

73.  51 

73.82 

74  14 

74-45 

74.76 

75  °8 

24 

75  39 

75-71 

76.O2 

76.34 

76.65 

76.96 

77.28 

77-59 

77.91 

78.22 

25 

78  54 

78  85 

79.16 

79.48 

79-79 

80.  ii 

80.42 

80.73 

81.05 

81.36 

26 
27 
28 

81.68 
84.82 
87.96 

81.99 

85-13 
88.27 

82.30 
85.45 

88.59 

82.62 
85.76 
88.90 

82.93 
86.07 
89.22 

$5 

89-53 

83.56 
86.70 
89.84 

83.88 
87.02 
90.16 

84.19 
87-33 
90.47 

84-50 
87.65 
90-79 

29 

91.  10 

91.42 

9i  73 

92.04 

92.36 

92.67 

92.99 

93.30 

936i 

93-93 

30 

94.24 

94-56 

94.87 

95.19 

95-50 

95  81 

96-13 

96.44 

96.76 

97.07 

31 

97.38 

97.70 

98.01 

98.33 

9864 

98.9699.27 

99-58 

99.90 

100.2 

32 

100.5 

100.8 

IOI.I 

101.4 

101.7 

102.  I  102.4 

102.7 

103  o 

i°3  •; 

33 
34 

103.6 
106.8 

103.9 
107.1 

104.3 
107.4 

104.6 
107.7 

104.9 
108.0 

105.2  105  5 
108.3  Io8  •(• 

105.8 

109.0 

106.1 
109.3 

109.6 

35109-9 

no.  2 

110.5 

no  8 

III.  2 

111.5  in.  8 

112.  I 

112.4 

II2-7 

RICHARDS     STEAM-ENGINE  INDICATOR. 


Circumferences  of  Circles,  advancing  by  lOths. 


Diameter.  | 

CIRCUMFERENCES. 

.0 

.1 

.2 

.3 

•4 

.5 

.6 

-7 

.8 

.9 

36 

113.0 

II3-4 

II3-7 

114.0 

114.3  II4.6 

II4.9 

II5.2 

IIS-6 

H5-9 

37 

116.2 

116.5 

II6.8 

117.1 

117.4  117.8  118.  1 

II8.4 

II8.7 

119.0 

38 

119.3 

II9.6 

120.0 

120.3 

120.6  120.9 

121.  2 

I2I.5 

121.  8 

122.2 

39 

122.5 

122.8 

I23.I 

123.4 

123.7:124.0 

124.4 

124.7 

125.0 

125-3 

40 

125.6125.9 

126.2  126.6 

I26.9|I27.2 

127.5 

127.8 

128.1 

128.4 

41 

128.8129.1 

129.4  I29«7 

I30.0I30.3 

130.6  I3I.O 

131.3 

I3I.6 

42 

131.9:132.2 

132.5132.8 

I33-2I33.5 

I33-8I34.I 

134.4 

134.7 

43 

135.0135.4 

135.7136.0 

136.31136.6 

I36.9I37.2 

137.6 

137.9 

44 

138.2138.5 

138.8  139.1 

139.4139.8 

I40.I  140.4 

140.7 

I4I.O 

45 

141.3  141.6 

142.0 

142.3 

142.6142.9^43.21143.5 

143.8 

I44.I 

46 

144-5144-8 

I45-1 

145-4 

145.7146.0146.3  146.7 

147.0 

147-3 

47 

147-6147-9 

148.2 

148.5 

148.9  149.2 

I49.5I49.8 

150.  1 

150.4 

48 
49 

150.7,151.1 
153-9154.2 

I5I-4 
154-5 

151-7 
154.8 

I52.O 
I55-I 

152-3 
155-5 

I52.6I52.9 
155.8  I56.I 

15^.3 

156.4 

153-6 
156.7 

5° 

157.0157.3 

157-7 

158.0 

158.3 

158-6 

158.9 

159.2 

159.5 

159.9 

51 

160.2 

160.5 

160.8 

161.1 

161.4 

161.7 

I62.I 

162.4 

162.7 

163.0 

52 

163.3163.6 

163.9 

164.3 

164.6  164.9  165.2 

165.5 

165.8 

I66.I 

53 

i66.5!i66.8 

167.1 

167.4 

167.7  168.0  168.3 

168.7 

169.0 

169.3 

54 

169.6 

169.9 

170.2 

170.5 

170.9171.2 

I7L5 

I7I.8 

172.1 

172.4 

55 

172.7 

I73.I 

173-4 

173-7 

174.0174.3 

174.6 

174.9 

175.3 

175.6 

56 

175-9 

176.2 

176-5 

176.8 

177.1 

177-5 

177.8 

I78.I 

178.4 

178.7 

57 

179.0 

179.3 

179.6 

180.0 

180.3 

180.6 

180.9 

181.2 

181.5 

181.8 

58 

182.2 

182.5 

182.8 

183.1 

183.4 

183-7 

184.0 

184.4 

184.7 

185.0 

59 

185-3 

185.6 

185.9 

186.2 

186.6 

186.9 

187.2 

187.5 

187.8 

188.1 

60 

188.4 

188.8 

189.1 

189.4 

189.7 

190.0190.3 

190.6 

191.0 

191-3 

61 

191.6 

I9I.9 

192.2 

192.5192.8 

193.2 

193-5 

193.8 

194.1 

194.4 

62 

194.7 

I95.O 

195-4 

195.7196.0 

196.3 

196.6 

196.9 

197.2 

197.6 

63 

197.9 

198.2 

198.5 

198.8199.1 

199.4 

199.8 

200.1 

200.4 

200.7 

64 

201.0 

201.3 

201.6 

202.0 

202.3 

202.6 

202.9 

203.2203.5 

203.8 

65 

204.2 

204.5 

204.8 

205.1 

205.4 

205.7 

206.O 

206.4206.7 

207.0 

66 

207-3 

207.6 

207.9 

208.2 

208.6 

208.9 

2O9.2 

209-5J209.8 

210.  I 

67 

210-4 

2I0.82II.I 

211.4211.7 

212.0 

212.3 

212.6213.0 

213-3 

68 

213.6 

2I3.92I4.2 

214.5214.8 

2I5.I 

215-5 

2i5.8'2i6.i 

216-4 

69 

216.7 

2I7.02I7.3 

217.7218.0 

218-3 

218.6 

218.9  219.2 

219.5 

70 

219.9 

22O.2|220.5 

220.8'22I.  I 

221.4 

221.  7  222.  1  '222.  4 

222.7 

88 


RICHARDS     STEAM-ENGINE   INDICATOR. 


Circumferences  of  Circles,  advancing  by  lOths. 


Diameter. 

CIRCUMFERENCES. 

.0 

.1 

.2 

•  3 

•4 

•5 

.6 

•7 

.  .8 

-9 

71 

223.0 

223.3 

223.6 

223.9224.3 

224.6224.9 

225.2 

225.5225  8 

72  226.  1 

226.5 

226.8227.1227.4227.7228.0 

228.3 

228.  7^29.  o 

73229-3 

229.6 

229.9  230.  2  230.  5(230.9  231  .  2 

231.5231.8232.1! 

74232.4 

232.7 

233-1 

233-4233-7 

234.0234.3 

234.6234.9235.3 

75235  6235.9 

236.2 

236.5236.8 

237-I237-5 

237   8238.1238.4 

76:238.7239-0 

239-3239-7 

24O.O 

240.3240.6 

240.9 

241.2241.5 

77241.9 

242.2242.5242.8243.1 

243  .  4  243  .  7 

244.1 

244.4244.7 

78 

245-0245.3245  61  245.  9  246  3 

246.6246.9 

247.2 

247.5247.8 

79 

248.1  248.5248.8249.  1)249.4 

249.7 

250.0 

250.3 

250.6251.0 

80 

251.3251.6 

25I-9252.2252.5 

252.8 

253.2 

253-5 

253.8254.1 

81 

254.4 

254.7255.0255.4255.7 

256.0236.3 

256.6 

256.9257.2 

82 

257.6257.9258.2258.5258.8 

259.8 

260.1 

260.4 

83 
84 
85 

260.7 
263.8 
267.0 

261.0261.3261.6262.0 
264  .  2  264  .  5  264  .  8  265  .  i 
267  .  3  267  .  6  267  .  9*268  .  2 

262.3262.6 
265.4265  7 
268.6268.9 

262.9 
266.0 
269.2 

263.2263.5 
266.4266.7 

269.5269.8 

86 

270.1 

270.4270.8271.1271.4271.71272.0 

272.3 

272.6273.0 

87 

273-3 

273-6273.9274.2274.5274.81275.2 

275  5 

275.8 

276.1 

88 

276.4 

276.7277.0 

277.4277.7278  0278.3 

278.6 

278.9279.2 

89 

279.6 

279.9280.2 

280.5280.8281.! 

281.4 

281.8 

282.1282.4 

90 

282.7 

283.0283.3 

283.6284.0284.3 

284.6284.9 

285.2285.5, 

91 

285.8 

286.1286.5 

286.8287.1287.4 

287.7288.0 

288.3 

288.7 

92 

289.0 

289.3289.6 

289.9290.2290.5 

29O-9!29I.2 

291.5 

291.8 

93 

292.1 

292  4292.7 

293-1293.4293  7 

294.0294.3 

294.6 

294.9 

94 
95 

295-3 
298.4 

295  6295.9 
298.7299.0 

296.2 
299-3 

296.5296  8 
299.7300.0 

297.11297-5 

300.31300.6 

297.8 
300.9 

298.1 
301.2 

96 

301.5 

301.9302.2 

302.5 

302.8303.1 

303.4 

303-7 

304-* 

304-4 

97 
98 

304  7 
307.8 

305-0305-3 
308.1308.5 

305  6 
308.8 

305.9306.3 
309.1309.4 

306.6 
309  7 

306.9 
310.0 

307.2 
310.3 

307-5 
310.7 

99 

100 

311.0 
3H  i 

311  33"  6 
314  4314.7 

3"  9 

315  -i 

312.2312.5 
3I5-43I5-7 

312.9 
316.0 

313   2 
316.3 

313.5 

316.6 

313.8 
316.9 

RICHARDS'  STEAM-ENGINE  INDICATOR. 


89 


If  the  areas  of  larger  cylinders  are  required,  they 
will  be  found  by  the  following  RULE  : — Multiply  the 
square  of  the  diameter  by  the  decimal  .7854,  and 
the  product  will  be  the  area  in  square  inches  ; 
or,  multiply  half  the  circumference  by  half  the 
diameter. 

TABLE  No.  IL 

Showing  the  weight  of  the  atmosphere,  in  Ibs.  avoirdupois,  on  1 
'square  inch,  corresponding  with  different  heights  of  the  barom- 
eter, from  28  inches  to  31  inches,  varying  by  tenths  of  an 
inch. 


Barometer 
in  Inches. 

Atmosphere 
in  Ibs. 

Barometer 
in  Inches. 

Atmosphere 
in  Ibs. 

! 
!  Barometer 
I  in  Inches. 

Atmosphere 
in  Ibs. 

28.0 

13.72 

29.1 

14.26 

i 
30.1 

14-75 

28.1 

13-77 

29.2 

H.3I 

30.2 

14.80 

28.2 

13.82 

29-3 

14.36 

30.3 

14  85 

28.3 

I3-87 

29.4 

14.41 

30-4 

14.90 

28.4 

13.92 

29.5 

14.46 

30-5 

14.95 

28.5 

13  97 

29.6 

14.51 

30.6 

15.00 

28.6 

14.02 

29.7 

14.56 

30-7 

I5-05 

28.7 

14.07 

29.8 

14.61 

30.8 

15.10 

28.8 

14   12 

29.0 

14.66 

30-9 

15-15 

28.9 

14.17 

30.0 

14.70 

31.0 

I5-I9 

29.0 

14.21 

RICHARDS'   STEAM-ENGINE   INDICATOR. 


Elastic  force  in 

Elastic  force  in 

Inches 

Pounds 

Tempe- 
rature. 

Volume. 

Inches 

Pounds 

Tempe- 
rature. 

Volume. 

of 

per 

of 

per 

Merc'y. 

Sq.  In, 

Merc'y  . 

Sq.  in. 

193.82 

95- 

328.2 

310 

306. 

150. 

363.4 

205 

203.99 
214.19 

100. 

105. 

332. 
335-8 

295 
282 

316.19      155- 
326.39!      1  60. 

366. 
368.7 

198 
193 

224.39 

no. 

339.2 

271 

336.  59(     165. 

37I-I 

187 

234.59 

ii5- 

342.7 

259 

346.^9     170. 

373-6 

I82 

244.79 

120. 

345-8 

251 

357-         175. 

376. 

178 

254-99 

125- 

349-1 

240 

367.2 

180. 

378.4 

174 

265    19 

130. 

352-1 

233 

377-1 

185. 

380.6 

169 

275-39 

135- 

355- 

224 

387.6 

190. 

382.9 

166 

285.59 
295-79 

140. 

145- 

357-9 
360.6 

218 
2IO 

397-8 
408. 

195- 

200. 

384.7 
387-3 

161 
158 

TABLE  No.  IV. 


No. 

Logarithm. 

No. 

Logarithm. 

No. 

Logarithm. 

1.25 

.22314 

5- 

.60943 

9-5 

2.25129 

i-5 

.40546 

5.25 

.  65822 

10. 

2.30258 

i  75 

.55961 

5-5 

.70474 

II. 

2.39789 

2. 
2.25 

.69314 
.81093 

I:75 

.74919 
•79175 

12. 
13- 

2.48490 
2.56494 

2-5 

2-75 

.91629 
.OIl6o 

625 
6.5 

•83258 
.87180 

14. 
15. 

2.63905 

3- 

.09861 

6.75 

.90954 

16. 

2.77258 

3  25 

.17865 

•94591 

17- 

2.83321 

3-5 

•25276 

7^25 

.98100 

18. 

2.89037 

3  75 

.32175 

7-5 

2.01490 

19. 

2-94443 

4- 

.38629 

7-75 

2.04769 

20. 

2-99573 

4-25 

.44691 

8. 

2.07944 

21. 

3-04452 

4-5 

4-75 

.50507 
•55814 

8.5 
9- 

2.14006 
2.19722 

22. 

3.09104 

RICHARDS    STEAM-ENGINE  INDICATOR. 


TABLE  No.  V. 

Table  of  Steam  used  Expansively. 


Average  Pressure  of  steam  in  Ibs,  per.  square  inch  for  the 

•whole  stroke. 

Initial 

Pressure, 
Ibs.  per 

Portion  of  stroke  at  which  steam  is  cut  off. 

square  inch. 

* 

X 

* 

% 

X 

* 

5 

4.8 

4.6 

4.2 

3-7 

2-9 

i.9 

10 

9.6 

9.1 

8.4 

7-4 

5-9 

3-8 

15 

14.4 

13-7 

12.7 

11.  i 

8.9 

5-7 

20 

19.2 

18.3 

16.9 

14.8 

11.9 

7-6 

25 

24.1 

22.9 

21.  1 

18.5 

14.9 

95 

28.9 

27-5 

25.4 

22.2 

17.9 

ii  5 

35 

33-8 

32.1 

29.6 

25.9 

20.8 

13  4 

40 

37-5 

36.7 

33-8 

29.6 

23.8 

15.4 

45 

g 

fti 

57-8 

4i-3 
45-9 

42-3 
50-7 

33-3 
37-o 
44-5 

26.8 
29.8 
35-7 

17.3 
19.2 

70 

67.4 

64.3 

59«2 

52-4 

41  -7 

26.9 

80 
90 

86*.  7 

IU 

67.7 
76.1 

si 

47-7 
53  6 

30-8 
34  6 

100 

96*3 

91.8 

84.6 

74-i 

59.6 

38.4 

no 

106.0 

IOI.O 

93«i 

81.5 

65.6 

42.5 

120 

115.2 

no.  2 

101.5 

89.4 

7i-5 

46.1 

130 
140 

125.4 
134.9 

119.1 
128.6 

IIO.O 

118.5 

95-3 
103.8 

77-5 
83-3 

50.0 
53-8 

% 

144.7 
153-6 

137-8 
147.0 

126.4 
135.4 

III   2 

118.2 

89-4 
95-4 

57-7 
61.5 

1  80 
200 

173-5 
192.7 

164.6 
183-7 

152-3 
169.3 

132.9 
148.3 

107.3 

76*9 

54  KICHARDS     STEAM-ENGINE   INDICATOR. 

We  insert  the  Table  No.  Y,  not  for  general  use  in 
•determining  the  mean  pressure,  as  we  have  seen  in 
the  example  on  page  62,  that  another  element,  the 
clearance,  has  to  be  taken  into  account  to  get  a  cor- 
rect result.  Now,  it  is  seldom  we  can  get  at  the 
drawings  or  patterns  to  get  the  measurement  of  the 
clearance,  hence  we  must  seek  some  other  mode. 

We  can  easily  find  if  the  engine  is  tight  or  not,  by 
taking  off  the  cylinder  cover,  putting  the  engine  on 
the  half  stroke,  blocking  the  fly-wheel,  and  letting 
«team  on  the  opposite  side  of  the  piston.  Suppose 
we  find  it  tight  in  valves  and  piston,  we  then  replace 
the  cover  and  take  some  diagrams,  and  find  the 
mean  by  measurement,  as  directed  on  page  62.  We 
then  refer  to  the  table  for  the  mean  pressure,  which 
will  be  found  too  low  when  compared  with  the  result 
l>y  measurement.  Then,  this  excess  given  by  meas- 
urement over  the  table  is  approximately  the  clear- 
ance. 

The  editor  is  responsible  for  the  above.  He  is 
;aware  that  it  is,  at  best,  but  an  approximation.,  owing 
to  the  condition  of  the  steam,  whether  wet  or  dry, 
influenced,  also,  by  the  point  of  cut-off,  pressure  of 
.steam,  etc.  The  engineer  has  to  adopt  this  mode, 
or  guess,  or  he  may  avail  himself  of  both. 

Where  time  and  circumstances  permit,  the  clear- 
ance may  be  accurately  found,  if  the  piston  is  tight, 
as  follows:  Put  the  engine  on  the  centre,  remove 
iihe  cover  of  the  valve  chest,  uncover  the  steam- 
port  on  the  end  where  the  piston  is,  and  pour  in 


RICHARDS    STEAM-ENGINE  INDICATOR.  9£ 

water  until  it  is  filled  level  with  the  valve  seat;  wait 
a  few  minutes,  and  if  it  maintains  its  level  we  know 
it  is  tight;  then  draw  off  the  water,  measure  or~ 
weigh  it,  reduce  it  to  cubic  inches,  and  we  have  it 
exactly.  Should  the  piston  leak,  we  remove  it  out 
of  our  way;  cut  a  segment  from  soft  wood  of  suffi- 
cient length  and  width  to  cover  the  port  at  its 
entrance  to  the  cylinder,  fasten  it  in  its  place,  and 
fill  with  water  as  above.  To  this  must  be  added 
the  clearance  between  piston,  when  on  the  centre 
and  cover. 

Again,  the  clearance  being  known  and  added, 
we  compute  them  by  measurement.  If  the  mean 
pressure  falls  short  of  that,  we  know  that  there  is 
a  leak  in  the  exhaust  valves  or  piston.  If  it  over- 
runs that,  we  know  the  cut-off  valves  leak.  Hence 
the  utility  of  the  table  is  to  make  those  point* 
manifest.* 


Cu' 

&rf 

CAUFr'**' 


RICHARDS'    STEAM-ENGINE    INDICATOR. 
DIAGRAM  No.  0. 


9T 


RICHARDS'    STEAM-ENGINE   INDICATOR.  99 


DIAGRAM    No.  1. 


Scale,  12  Ibs.  to  the  inch. 


RICHARDS'  STEAM-ENGINE  INDICATOR.  101 

DIAGRAM  No.   2. 


200  revolutions  per  minute.    132  Ibs.  pressure  of  steam  cut 
off  at  second  notch. 


RICHARDS'   STEAM-ENGINE    INDICATOR.  103 

DIAGRAM  No.  3. 


200  revolutions  per  minute.     109  Ibs.  pressure  of  steam  cut 
off  at  second  notch. 


&.' 

ji>  ,R 6 1 T  Y 

^^(.: 


RICHARDS'    STEAM-ENGINE    INDICATOR.  105 

DIAGRAM    No.  4. 


revolutions  per  minute.     105  Ibs.  pressure  of  steam  cut 
off  at  first  notch. 


RICHARDS'  STEAM-ENGINE  INDICATOR.  .         107 
DIAGRAM   No.    5. 


224  revolutions  per  minute.     107  Ibs.  pressure  of  steam  cut 
oft' at  first  not cli. 


RICHARDS'    STEAK-ENGINE    INDICATOR.  109 


TVEBSIT*  J 

\,C 


BICHARDS'    STEAM-ENGINE    INDICATOR.  Ill 

DIAGRAM    No.  7. 


A,  termination  of  correct,  expansion  curve. 


RICHARDS     STEAM-ENGINE    INDICATOR. 

DIAGRAM  No.   8. 


113 


RICHARDS'    STEAM-ENGINE    INDICATOR.  115 

No.  9. 


RICHARDS'    STEAM-ENGINE   INDICATOR.  117 


DIAGRAM    No.  10. 


BICHABDS'    STEAM-ENGINE    INDICATOR. 


119 


DIAGRAM  No.   II. 


Of  THE 

XJNIVEESITT 


BICHARDS'    STEAM-ENGINE     INDICATOR.  121 


DIAGRAM   No.  12. 


BICHAUDS'    STEAM-ENGINE    INDICATOR.  123 


DIAGRAM    No.  13. 


KICHAItDS'    STEAM-ENGINE    INDICATOR.  125 

K 


DIAGRAM    No.  14. 


RICHARDS'  STEAM-ENGINE  INDICATOR. 
DIAGRAM  No.  15. 


127 


[(  UNIT  -{   » 


B1OHARDS'    STEAM-ENGINE    INDICATOR. 

DIAGRAM  No.  16. 


BICHABDS'    STEAM-ENGINE    INDICATOR. 
DIAGRAM  No.  17. 


BICH  ABBS'    STEAM-ENGINE    INDICATOR. 

DZAORAXKI  No.  18. 


133, 


?BIT 


m 


>         1 


EICIIARDo'    STEAM-ENGINE    INDICATOR.  135 

DIAGRABI  No.   19. 


Back  and  forward. 


RICHARDS'    STEAM-ENGINE   INDICATOR.  137 


DIAGRAM    No.  20. 


tf 

RICHAliDS'    STEAM-ENGINE  WlCA3$£\f  <  139 


DIAGRAM    No.  21. 


RICHARDS     STEAM-ENGINE    INDICATOR. 

DIAGRAM  No.   22. 


141 


RICHARDS'    STEAM-ENGINE    INDICATOR. 


143 


APPENDIX. 


USEFUL    INFORMATION. 

Cement  for  Steam  Joints. 

Take  a  quantity  of  pure  red  lead,  put  it  in  an 
iron  mortar  or  on  a  block  or  thick  plate  of  iron. 
Put  a  quantity  of  pure  white  lead  ground  in  oil; 
knead  them  together  until  you  make  a  thick  putty, 
then  po?md  it ;  the  more  it  is  pounded  the  softer  it 
will  become.  Koll  in  red  lead  and  pound  again ; 
repeat  the  operation,  adding  red  lead  and  pound- 
ing until  the  mass  becomes  a  good  stiff  putty.  In 
applying  it  to  the  flange,  it  is  well  to  put  a  thin 
grummet  around  the  orifice  of  the  pipe  to  prevent 
the  cement  being  forced  inward  to  the  pipe  when 
the  bolts  are  screwed  up.  The  more  pounding  the 
better. 

Another,  to  be  used  when  the  flanges  are  not 
faced :  Make  the  above  mass  rather  soft  and  add 
cast-iron  borings,  pounding  in  thoroughly  until  it  is 
sufficiently  soft  to  spread. 

Both  the  above  are  the  most  durable  cements 
known  to  the  engineer.  They  will  resist  fire  and 
set  in  water. 


140          RICHARDS'  STEAM-ENGINE  INDICATOR. 

Another  (English),  said  to  be  very  good  :  Take 
10  Ibs.  ground  litharge,  4  Ibs.  ground  Paris  white, 
\  Ib.  yellow  ochre,  J  oz.  of  hemp  cut  into  lengths  of 
J';;  mix  all  together  with  boiled  linseed  oil  to  the 
consistence  of  a  stiff  putty.  Resists  fire  and  will 
set  in  water.  [Pounding  would  improve  it. — ED.] 

A  Good  Dressing  for  Leather  Belts. 

One  part  of  beef  kidney  tallow  and  two  parts  of 
castor  oil,  well  mixed  and  applied  warm.  It  will 
be  well  to  moisten  the  belt  before  applying  it. 

No  rats  or  other  vermin  will  touch  a  belt  after 
one  application  of  the  oil.  It  makes  the  belt  soft, 
and  has  sufficient  gum  in  it  to  give  a  good  adhesive 
surface  to  hold  well  without  being  sticky. 

A  belt  with  a  given  tension  will  drive  34  per  cent, 
more  with  the  grain  or  hair  side  to  the  pulley  than 
the  flesh  or  rough  side. 

Rules  for  Calculating  Belting. 

This  is  one  of  the  most  difficult  problems  the 
engineer  has  to  solve.  There  are  so  many  different 
conditions  attending  the  conveying  of  power  by  belts 
that  no  definite  rule  can  be  given.  I  have  found, 
however,  that  where  the  conditions  are  fair  to  mid- 
dling, that  a  belt  one  inch  wide,  running  800  feet 
per  minute,  is  equal  to  one  horse  power.  Increased 
width  in  proportion.  This  will  do  the  work  under 
a  safe  and  proper  tension.  There  are  conditions, 


RICHARDS'  STEAM-ENGINE  INDICATOR.  147 

however,   which   might  require   double    the   above 
width  or  speed. 

How  to  make  belts  run  on  the  centres  of  pulleys. 

It  often  happens  that  a  belt  will  persist  in  run- 
ning on  one  side  of  the  pulley. 

In  this  case  one  or  more  things  cause  it.  First, 
one  or  both  of  them  may  be  conical,  and  of  course 
the  belt  would  run  on  the  higher  side.  Second,  the 
shafts  may  not  be  parallel ;  in  this  case  the  belt 
would  incline  off,  on  the  side  towards  where  the 
ends  of  the  shaft  are  nearest  to  each  other.  The 
remedy  in  this  case  is,  to  make  them  parallel  to 
each  other  by  carrying  the  ends  of  the  shaft  towards 
which  the  belt  inclines,  farther  apart. 

In  giving  rules  for  calculating  the  horse-power  of 
belts,  we  would  not  be  understood  as  saying  that  a 
belt  will  not  do  more  than  the  rule  would  give  ;  on 
the  contrary,  we  know  that  double  and  even  more 
power  may  be  transmitted  by  them  by  a  sufficient 
tension,  which  would  create  a  ruinous  amount  of 
friction  and  a  speedy  destruction  of  the  belt.  "We 
would  be  understood  to  say  that  the  rules  give  data 
for  a  belt  that  will  run  with  a  moderate  and  safe 
tension.  The  attempt  often  made  to  calculate  the 
work  that  a  belt  of  given  width  and  travel  in  feet 
per  minute  without  any  known  tension  is  doing,  or 
will  do,  is  very  like  comparing  the  size  of  a  pebble- 
stone to  a  piece  of  chalk.  The  Indicator  tests  that 
with  certainty. 


148          RICHARDS'  STEAM-ENGINE  INDICATOR. 

The  practice  of  putting  an  idler  against  a  belt  to 
make  it  drive  is  a  most  pernicious  one,  destructive 
alike  to  the  belt  and  power ;  its  only  merit  is  to 
disguise  bad  engineering. 

Measuring  Steam  used  for  heating. 

The  engineer  is  often  called  to  determine  the 
amount  of  steam  that  is  used  to  heat  apartments, 
liquids,  etc.  This  the  Indicator  does  not  reveal 
directly,  no  farther  than  it  shows  how  much  steam 
it  requires  for  a  horse-power  ;  varied,  of  course,  by 
the  point  of  cut-off  and  its  efficiency. 

Under  these  circumstances  we  have  followed  the 
rule  of  Watt,  which  is  to  allow  one  cubic  foot  of 
water  per  hour  for  each  horse-power ;  hence  we 
measure  the  water  condensed  in  the  heating  pipes 
in  a  given  time,  and  estimate  accordingly. 

If  it  is  inconvenient  to  reduce  the  water  to  cubic 
feet,  it  may  be  weighed,  allowing  62.5  Ibs.  to  the 
cubic  foot,  or  it  may  be  measured  by  the  gallon,  or 
7.48  gallons  per  cubic  foot. 

When  the  steam  pipe  enters  the  vessel  and  it  dis- 
charges the  steam  directly  into  the  liquid  to  be 
heated,  the  water  then  cannot  be  caught  to  be 
measured  ;  in  that  case  we  measure  the  increment 
of  its  contents,  and  thereby  find  the  quantity  of 
steam  condensed. 


RICHARDS'  STEAM-ENGINE  INDICATOR. 

Condensation  of  pipes  and  coils. 

Steam  pipes  in  the  ordinary  circulation,  such  as 
are  used  to  warm  buildings,  when  one  or  more  run 
around  the  sides  of  the  apartment,  having  and 
maintaining  a  temperature  of  60°,  will  condense 
.357  Ibs.  of  water  per  hour  for  each  square  foot  of 
surface  of  pipe. 

A  coil  maintaining  the  same  temperature  will 
condense  .29  Ibs.  per  hour  per  square  foot  of  sur- 
face. 

The  radiating  surface  of  steam  pipe  required  to  warm 
buildings  and  apartments. 

This  varies  in  consequence  of  the  character  of  the 
structures,  the  exposure,  the  quantity  of  glass, 
the  use  the  space  required  to  be  heated  is  put  to, 
climate,  etc. 

In  the  city  of  New  York  the  data  of  calculation, 
modified  by  the  above-mentioned  circumstances,  is 
this  : 

For  dwellings — when  the  pipes  in  form  of  a  coil 
are  placed  in  the  cellar  and  supplied  with  air  from 
outside — one  square  foot  of  pipe  surface  to  50  cubic 
feet  of  apartment  to  be  warmed. 

When  the  coil  is  placed  in  the  apartment,  one 
square  foot  of  surface  of  pipe  to  65  cubic  feet  of 
space. 

In  stores  and  warehouses,  one  square  foot  of  pipe 
surface  to  175  to  200  cubic  feet. 


150          RICHARDS'  STEAM-ENGINE  INDICATOR. 

In  workshops,  one  square  foot  of  pipe  surface  to 
100  cubic  feet  of  space. 

Heating  with  exhaust  steam  is  of  questionable 
economy.  It  is  not  economical,  certainly,  when 
used  in  small  pipes,  in  consequence  of  the  power 
required  to  force  the  steam  through  them.  We 
have  seen  exhaust  steam  used  economically  in  work- 
shops and  factories  where  it  is  permissible  to  use 
large  cast-iron  pipes,  which  present  so  much  less 
friction  surface  in  proportion  to  the  area,  that  the 
power  used  to  force  the  steam  into  them  shows  but 
a  small  back  pressure  on  the  engine — 1  or  1|  lfos.  per 
square  inch — if  the  pipes  are  of  sufficient  size  and 
properly  arranged.  We  have  found  the  following 
to  work  well  in  practice  : 

We  use  for  the  smallest,  flanged  pipe,  without  re- 
gard to  the  size  of  the  engine,  4"  diameter.  If  it 
is  required  to  be  over  75  feet  in  length,  we  use  5"  ; 
if  over  100  feet,  we  use  6". 

The  pipes  should  be  f  thick,  with  flanges  at 
least  4  inches  larger  than  the  outside  diameter  of 
the  pipe. 

These  flanges  should  be  faced  so  as  to  have  a  fair 
bearing  over  the  whole  surface,  and  when  faced,  not 
less,  than  f"  thick,  fastened  with  five  bolts,  I"  diame- 
ter. We  place  them,  when  practicable,  around  the 
walls  of  the  room,  near  the  floor,  on  the  sides  most 
exposed,  giving  them  an  inclination  of  not  less  than 
one  inch  in  ten  feet ;  for  our  joints,  the  cement  No.  1 
(rubber  not  permissible). 


RICHARDS'  STEAM-ENGINE  INDICATOR.  15J 

The  main  exhaust  pipe  we  carry  out  of  the  build- 
ing, without  reference  to  our  heating  pipes,  except 
to  have  a  nozzle  to  carry  off  steam  to  the  highest 
end  of  the  heating  pipe.  Should  there  be  one  or 
more  rooms  above  or  below,  separate  pipes  fron* 
the  main  should  be  led  off  in  the  same  way.  The? 
drain  pipes  should  be  at  the  lowest  end  of  the  piper 
and  J"  to  |"  diameter.  If  it  is  desirable  to  let 
only  water  escape,  a  siphon  may  be  fixed  to  the- 
end  of  the  tail  pipe,  with  legs  of  sufficient  length 
to  overbalance  the  steam  pressure,  yet  leaving  the- 
water  by  its  superior  gravity  to  escape. 

The  supports  should  be  firmly  fixed  to  the  wallr 
in  perfect  line  with  each  other,  that  there  be  no> 
bend  or  low  place  for  the  water  to  collect,  which 
would  inevitably  destroy  the  pipe. 

We  have  used  a  system  of  pipes  arranged  as 
above,  for  eight  years,  without  the  least  attention 
to  them-.  Not  a  joint  Jias  leaked. 

Since  the  publication  of  the  first  edition,  I  have 
seen  exhaust  steam  used  in  1J-"  pipes  with  good  re- 
sult, and  with  but  little  back  pressure.  The  arrange- 
ment was  to  take  the  steam  off  the  main  pipe  inta 
4 — 4J"  pipe,  from  the  right  and  left  side,  carried 
around  on  each  side  of  the  rooms.  At  the  termina- 
tion of  each  coil,  a  pipe  2"  diameter  carried  off  the 
water  and  uncondensed  steam.  The  back  pressure- 
shown  was  less  than  2  Ibs. 

It  is  not  safe  to  allow  steam  pipes  in  contact  with 
wood. 


152  RICHARDS'  STEAM-ENGINE  INDICATOR. 

Value  of  Pea  and  Dust  Coal,  as  compared  with  lump 
of  good  merchantable  quality,  with  a  blast  induced 
by  "  Hancock's  Steam  Blower." 

2,000  Ibs.  of  pea  and  dust,  the  screenings  from 
the  coal-yards,  have  been  found  equal  to  1,600  Ibs. 
of  lump.  This  is  a  result  of  several  weeks'  trial 
with  the  same  engine  and  boiler  doing  the  same 
work. 

Gauge  glasses,  when  required. -to  be  cleaned, 
should  have  a  wooden  swab-stick.  A  metallic  one 
will  cause  the  tube  to  fall  to  pieces  inevitably,  and 
sometimes  immediately. 

Value  of  Cumberland  coal  as  compared  with 
anthracite.  Two  tons  (4,000  Ibs.)  of  anthracite 
furnished  steam  for  an  engine  seven  days.  The 
same  amount  of  Cumberland  served  the  same 
engine,  everything  else  the  same,  eight  days. 

This  experiment  was  continued  with  alternate 
changes  for  two  months. 

Boiler,  locomotive  type,  with  natural  draft. 


When  there  are  indications  of  an  extraordinary 
corrosion  of  the  steam-boiler  and  its  fittings,  the 
gauge-cocks  and  valves  leak.  Acid  is  suspected. 
Test  it  by  putting  into  a  sample  of  the  water  a  strip 
of  litmus  paper  ;  if  acid 'is  present,  the  purple  paper 
will  be  changed  to  red. 


RICHARDS'    STEAM-ENGINE    INDICATOR.  153 

To  ascertain  if  iron  is  in  solution,  put  into  the 
samples  a  few  grains  of  tannic  acid  ;  if  iron  is 
present,  it  will  immediately  become  a  dark  purple  or 
black. 

The  writer  has  found  two  cases  where  the  wells 
that  supplied  steam-boilers  were  poisoned  by  the 
spent  irickle  finding  its  way  into  the  wells,  thence  to 
the  boilers,  and  was  detected  as  above.  The  iron 
(sulphate)  was  so  abundant,  when  a  proper  quantity 
of  tannin  was  put  in,  it  formed  a  sufficient  ink  so 
that  the  report  of  the  examination  was  written  with 
it.  F.  W.  B. 

Water  when  converted  into  steam  can  heat  about 
6  times  its  own  weight  of  well  water  to  212°  Fahr. 

JAMES  WATT. 

Sir  Wm.  Fairbairn  found,  by  a  series  of  experi- 
ments, that  in  constructing  internal  flues  for  boilers, 
when  the  pressure  was  from  outward  to  the  center 
(centripetal),  that  as  the  length  was  increased,  the 
thickness  of  plate  must  be  increased  in  direct  pro- 
portion. That  is,  if  £-inch  plate  was  right  for  a 
10  ft.  length,  if  the  flue  was  20  ft.  in  length,  the 
plate  must  be  i  inch  to  stand  the  same  pressure. 

Dressing  for  an  Emery  Wheel,  to  give  a  fair  polish,  say 
such  as  is  usual  on  carpenter's  tools. 

The  tool  has  been  surfaced  on  a  wheel  covered 
with  No.  60  emerv.  Take  another  wheel  covered 


154  RICHARDS'    STEAM-ENGINE   INDICATOR. 


same  No.,  and  rub  on  a  composition  of  flour, 
•emery  and  beeswax.  Set  the  wheel  running  and 
hold  on  a  flint  ;  again  rub  on  the  composition  and 
.again  the  flint,  until  it  gives  the  polish  required. 

To  make  the  composition,  melt  the  wax  with  a 
gentle  heat  ;  stir  the  emery  in  until  it  is  thick  ; 
Temove  the  heat,  and  keep  up  the  stirring  until  it  is 
.-so  cool  that  the  emery  won't  fall  to  the  bottom. 

The  wheel  must  be  kept  nicely  balanced,  or  the 
polish  will  be  cloudy.  F.  W.  B. 

To  Cool  Off  a  Hot  Bearing. 

Take  off  the  top  box,  and  while  the  shaft  is  slowly 
turning,  put  on  white-lead  ground  in  oil  from  the 
leg.  When  the  lead  is  seen  coating  the  bearing  as 
it  turns  slowly,  it  shows  that  the  lead  has  interposed 
itself  between  the  two  surfaces  and  will  cool  down, 
when  the  ordinary  lubricant  may  be  resumed. 

F.  W.  B. 

Water  j  Scales  the  Boiler.     Lime  is  suspected. 

TEST.  —  Into  a  tumbler  containing  the  suspected 
water  put  8  or  10  grains  of  oxalic  acid  ;  if  lime  is 
present,  the  water  will  become  milky,  and  after 
standing  quiet  awhile,  the  lime  will  be  precipitated 
•(oxalate  of  lime). 

Should  the  precipitate  not  show  itself,  add  a  little 
ammonia,  which  is  a  more  delicate  test.  If  no  pre- 
cipitate is  shown,  it  is  not  lime  that  forms  the  scale. 

F.  W.  B. 


RICHAliDS'    STEAM-ENGINE    INDICATOR.  155 

For  Calculating  the  Horse-powers  of  a  Given  Quantity 
of  Water  in  a  Given  Time,  7,000,000  gallons  of  Water 
passing  through  the  Turbine  in  60  hours. 

KULE. — Multiply  the  fall  in  feet  by  .3682.  The 
product  is  the  horse -powers,  net.  This  is  a  unit.  If 
there  is  more  or  less  water,  or  more  or  less  time,  the 
horse-power  developed  will  be  more  or  less  in  direct 
proportion. 

From  testimony  of  J.  B.  FRANCIS,  C.  E. 

ANOTHER  RULE. — 8.8  cubic  feet  of  water  per  second 
falling  one  foot  is  equal  to  one  horse-power. 

From  testimony  of  C.  HERSCHEL,  C.  E. 

The  Inspirator 

supplies  the  steam-boiler  with  water  cheaper  than  the 
steam-pump.  F.  W.  B. 

Memorandum. 

It  is  bad  practice  to  pack  the  joints  of  steam- 
chests,  cylinder-heads,  etc.,  with  rubber  ;  in  fact,  any 
joint  that  is  exposed  to  heat,  as  the  sulphur  used  in 
volcanizing,  disintegrates  the  cast  iron  and  erodes 
the  bolts  inevitably  in  tim?.  It  may  be  tolerated  in 
the  manhole  of  the  boiler.  F.  W.  B. 


RICHARDS-THOMPSON'S    STEAM-ENGINE    INDICATOR. 


156 


SUPPLEMENT 

TO    THE 

PORTER-BACON  TREATISE  ON  THE 

EICHARDS  STEAM-ENGINE  INDICATOR; 


BEING   NOTES   ON  THE 


RICHARDS-THOMPSON   INDICATOR, 

THE  AMSLER  POLAR-PLANIMETER  AND  THE  PANTOGRAPH, 
AS  USED  IN  CONNECTION  WITH  THE  INDICATOR. 


By  F.  W.  BACON,  M.  E., 
Member  of  the  American  Society  of  Civil  Engineers. 


1879. 


157 


THE 


RICHARDS-THOMPSON 

STEAM-ENGINE  INDICATOR, 


rTIHE  constant  demand  for  high  piston  speed  of 
-A-  stationary  and  locomotive  engines,  has  outrun 
the  capacity  even  of  the  Kichards  instrument,  and 
rendered  it  imperative,  if  we  would  have  a  correct 
result,  that  an  instrument  be  produced  that  would 
meet  the  call.  Therefore,  "necessity  being  the 
mother  of  invention,"  the  patentee  has  given  us  the 
instrument  which  is  all  that  can  be  desired.  It  is 
believed  that  it  will  give  correct  results  under  any 
attainable  speed  of  a  steam-engine.  It  will  be  ob- 
served that  Mr.  Thompson's  improvement  mainly 
consists  in  reducing  the  weight  43.65  per  cent  of 
the  parallel  motion,  by  reducing  the  number  of 
vibrating  pieces,  thereby  reducing  the  tendency  to 
make  wavy  lines  in  both  steam  and  expansion.  By 
the  new  arrangement  the  instrument  is  lighter  and 
more  compact,  qualities  that  will  be  fully  appreciated 
by  the  engineer. 

159 


160  RICHARDS-THOMPSON   INDICATOR. 

With  these  improvements,  and  the  facilities  pro- 
vided for  the  attachment  of  the  instrument,  it  is 
obvious  that  the  engineer  in  charge  should  be  edu- 
cated to  its  use,  and  required  to  make  weekly  reports 
of  power  indicated  and  fuel  expended. 

The  Indicator  is  the  light  to  the  engineer's  eye : 
without  it  he  gropes  in  the  dark  ;  he  can't  set  his 
valves  correctly  ;  he  has  no  mode  of  measuring  the 
power  even  approximately  without  it ;  hence  he  can 
make  no  comparative  test  of  fuel  used  and  power 
eliminated  ;  he  may  be  burning  10  or  15  Ibs.  of  coal 
per  hour  per  horse-power,  when  he  should  burn  but 
2J  to  3  Ibs.  per  hour  per  horse-power ;  a  most  scan- 
dalous and  wicked  waste  of  fuel. 

The  locomotive  presents  a  great  field  for  its  appli- 
cation, though  as  yet  but  partially  cultivated.  Those 
master  mechanics  who  have  had  the  courage  to  apply 
it,  and  have  followed  its  indications,  have  shown 
most  curious  results,  which  have  prompted  a  change 
in  valve  gear,  valve  settings,  enlargements  of  ports 
and  thoroughfares,  an  increase  in  the  areas  of  noz- 
zles, etc. 

The  following  diagram  (No.  1),  taken  by  J.  A. 
Lauder,  Esq.,  M.  M.,  of  the  Northern  (N.  H.)  Rail- 
road, is  one  of  the  many  taken  from  engines  under 
his  charge,  which  he  has  kindly  furnished  me  ;  it  is 
not  an  exceptional  one.  It  will,  however,  be  hard  to 
find  its  superior.  To  attain  this  excellence,  he  fol- 
lowed the  dictation  of  the  Indicator.  Its  mate  from 
the  other  end  is  o.fac-simile. 


BICHARDS-THOMPSON    INDICATOR. 


162  RICHARDS-THOMPSON    INDICATOR. 

The  LOCOMOTIVE,  MOGUL  PATTERN,  of  the  following 
description  : 

WOOD   BURNER. 

Cylinders,  17  x  24  in.  ;  diameter  of  wheel,  54  in. ; 
admission  ports,  16x1^  in.;  exhaust  ports,  16  x  2  j 
in.;  outside  lap,  -J  in.;  inside  lap,  -J-  in.;  travel  of 
valve,  5  in.;  lead  full  gear,  ^  in. ;  boiler  pressure, 
1 30  Ibs. ;  cutting  off  at  12  in. ;  exhaust  nozzles,  two, 
3  in.  diameter  ;  revolutions,  50  per  minute  ;  scale  of 
instrument,  60  to  one  inch. 


DIAGRAM    NO.  2 

is  introduced  to  supply  information  to  beginners,  who 
will  sometimes,  when  getting  diagrams  from  engines 
without  any  or  but  little  load,  find  the  expansion 
curve  fall  below  the  atmospheric  line,  showing  a 
partial  vacuum  behind  the  piston,  and  are  often  at 
loss  how  to  account  for,  or  what  to  do  with  it. 
The  writer  does  not  remember  having  seen  it  men- 
tioned in  any  of  the  books,  and  having  known  of 
some  rather  ridiculous  blunders  made  in  disposing 
of  it,  ventures  to  take  it  up  and  explain  it,  though  it 
may  seem  to  the  expert  unnecessary. 

This  "  loop  below  "  is  made  by  the  advancing  piston 
passing  the  point  due  to  reducing  the  volume  of  steam 
by  expansion  to  the  atmospheric  pressure — at  that 
point  the  expansion-curve  crosses  the  atmospheric 
line,  and  might,  under  certain  circumstances,  create 


RICHARDS-THOMPSON    INDICATOR. 

nearly  a  perfect  vacuum,  were  it  not  for  the  presence 
of  water,  which  re-evaporates  and  partially  fills  the 
space. 

In  treating  this  loop,  it  must  be  measured  out,  the 
same  as  any  back  or  negative  pressure.  It  don't 
suffice  not  to  measure  it  in — measure  the  diagram 
without  including  it,  then  measure  it,  and  deduct  it 
from  the  sum  of  first  measurement.  This  "  loop " 
incidentally  serves  a  very  important  purpose,  inso- 
much as  its  presence  shows  that  there  is  no  leak 
either  in  the  valves  or  piston.  9 


EICHAKDS-THOMPSON    INDICATOR. 


DIAGRAM   No.   2. 


RICHARDS-THOMPSON    INDICATOB.  165 

The  following  diagram  (No.  3)  is  introduced  as 
one  of  the  most  perfect  that  is  obtained  from  a  high- 
pressure,  non-condensing  engine.  It  was  taken  with 
the  Thompson  Indicator,  actuated  by  the  Panto- 
graph, from  "  The  Brown''  engine,  16"  x  42  "x  60 
revolutions,  exhibited  at  the  Fair  of  the  Massachu- 
setts Charitable  Mechanic  Association.  When  we 
consider  the  speed  of  the  piston,  420  ft.  per  minute, 
the  steam  pressure,  67  Ibs.,  scale  40,  we  think  un- 
commonly perfect  lines  are  shown,  especially  the 
steam  line  and  expansion  curve.  It  shows  also  a- 
most  prompt  and  perfect  action  of  the  admission  and 
eduction  valves ;  the  point  of  cut-off  is  sharp, 
decided,  and  unmistakable,  qualities  that  will  be 
fully  appreciated  by  the  engineer. 

It  is  one  of  many  hundred  diagrams  taken  by 
the  writer  from  the  engine  during  the  exhibition, 
all  with  the  same  characteristics. 

Should  any  one  wish  to  make  the  theoretic  curve 
around  the  diagram,  we  give  in  addition  to  the  above 
data  the  clearance,  2£  per  cent. 


166 


RICHARDS-THOMPSON    INDICATOR. 


DIAGRAM   No.   3- 


RICHARDS-THOMPSON    INDICATOR.  167 

For  reducing  the  motion  of  the  piston  to  the 
required  length  of  the  diagram,  there  are  many 
devices.  The  one  most  in  use  is  a  strip  of  board 
suspended  from  the  ceiling  above,  or  carried  off 
horizontally,  as  circumstances  dictate,  and  it  often 
requires  considerable  ingenuity  to  effect  it  without 
too  much  cost  ajid  delay.  The  pendulum  should  be 
not  less  than  one  and  one-half  the  length  of  the  piston- 
stroke  from  the  point  of  suspension  to  the  point  of 
attachment  to  the  cross-head  ;  if  longer,  say  twice 
the  length  of  the  stroke,  it  is  better. 

To  find  the  point  of  attachment  of  the  line  leading 
off  to  the  indicator,  the  following  is  the 

RULE. — Divide  the  length  of  piston-stroke  in  inches 
by  the  required  length  of  the  diagram  ;  divide  the 
length  of  the  pendulum  in  inches  by  the  above  quo- 
tient, and  this  quotient  is  the  distance  in  inches  from 
the  point  of  suspension  to  the  point  of  attachment 
of  the  line,  approximately. 

EXAMPLE. — Stroke  of  piston,  36".  Length  of  re- 
quired diagram,  4.5".  Length  of  pendulum,  54". 

Then  36"-=-4.5  —  8.     54^8  =  6.75. 

Or,  4.5  )  36.0  (  8 

36.0 

8  )  54  (  6.75"  from  point  of  suspension  to 
48  attachment  of  line. 

60 
56 
40 


168  RICHARDS-THOMPSON    INDICATOR. 

Tliis  is  approximate,  but  not  mathematically  cor- 
Tect,  owing  to  the  arc  of  a  circle  described  by  both 
^points  of  attachment,  yet  is  considered  sufficiently 
.accurate  for  practical  purposes.  The  pantograph 
:gives  us  a  correct  result. 

On  page  24  of  the  "Treatise,"  and  onward,  the 
question  of  the  mode  of  giving  mption  to  the  Indi- 
cator is  discussed.  Since  that  was  published,  there 
has  been  a  new  mode  applied,  which  is  invaluable, 
insomuch  as  it  is  mathematically  correct,  can  be 
applied  in  almost  any  case,  renders  long  lines  and 
•carrying  pulleys  unnecessary,  is  compact  and  port- 
able, being  when  folded  about  18"  long  by  3"  x  5". 
It  is  known  as  the  Indicator  Pantograph.  It  is  fur- 
nished with  or  without  the  instrument,  when 
required.  It  is  an  old,  well-known  device,  applied 
to  a  new  purpose. 

If  the  Indicator  is  applied  to  the  side  of  the  cylin- 
der, it  enables  us  to  use  short  cords,  without  the  use 
of  carrying  pulleys  to  lead  the  cord  to  the  Indicator. 
We  would  advise  the  operator  to  use  the  Raided 
cord,  as  it  is  far  less  elastic. 

A  medal  was  awarded  to  the  Indicator  Pantograph 
ut  the  late  Mechanics'  Fair  of  Massachusetts. 

Since  the  second  edition  of  the  Treatise  was  pub- 
lished, an  instrument  for  measuring  and  computing 
diagrams  has  been  introduced.  It  can  be  used  also 
to  measure  any  other  irregular  or  regular  form 
within  its  compass.  It  is  known  as 


AMSLEK'S    POLAR-PLANIMETER. 


170  AMSLER'S    POLAB-PLANIMETER. 

Its  use  greatly  diminishes  liability  to  error;  and 
the  great  aid  it  affords  to  the  quick  and  accurate 
computation  of  diagrams,  renders  its  use  indispensa- 
ble, especially  to  engineer  experts  who  are  employed 
to  make  special  tests  of  long  duration,  where  a  thou- 
sand, more  or  less,  of  diagrams  are  to  be  calculated. 
Also  to  the  ordinary  engineer  who  takes  indicator 
cards  for  the  purpose  of  adjusting  his  valves  and 
calculating  the  power  of  his  engine  ;  no  matter  what 
the  shape  of  the  diagram  is,  whether  the  lines  and 
curves  are  straight  or  jagged,  waving  or  serrated, 
the  instrument  follows  them  accurately  and  gives  a 
correct  measurement. 

It  will  be  seen  by  the  engraving  that  the  instru- 
ment has  two  legs,  with  a  joint  at  the  top  like  a  pair 
of  dividers,  with  the  right-hand  leg  shorter  than  its 
mate  ;  to  the  short  leg  is  attached  a  cylinder  (7,  with 
a  projecting  flange,  which  revolves  freely  on  its  axis. 
The  cylinder  is  divided  into  ten  grand  divisions,  and 
marked  1—2—3—4—5—6—7—8—9—0.  Now  as 
the  wheel  rolls  around,  each  one  of  these  divisions 
represent  one  square  inch.  Each  one  of  these  grand 
divisions  is  subdivided  into  ten  spaces  representing 
one  tenth  of  a  square  inch.  But  this  is  not  fine 
enough  ;  we  want  to  measure  hundredths.  To  effect 
this,  we  use  the  Vernier  scale,  which  in  this  case  is  a 
segment  of  a  circle,  same  diameter  as  the  cylinder, 
whose  edges  are  put  in  juxtaposition  with  each  other, 
but  allowing  the  latter  to  revolve  without  touching. 
This  segment  has  one  grand  division  just  correspond- 


AMSLEB'S   POLAR-PLANIMETEE.  171 

ing  to  nine  of  the  subdivisions  on  the  cylinder.  This 
grand  division  is  subdivided  into  ten  spaces,  and 
marked  0 — 5—10.  This  segment  is  firmly  fixed  to 
the  head  of  the  instrument,  so  that  the  edge  of  it 
exactly  corresponds  with  the  edge  of  the  revolving 
cylinder.  It  is  called  the  Vernier  scale.  With  these 
relative  positions,  the  graduations  come  opposite 
each  other,  but  as  the  spaces  are  not  the  same  on 
each,  it  is  evident  that  but  one  mark  on  each  can  be 
opposite. 

HOW    TO    USE    THE    INSTRUMENT. 

Fasten  the  diagram  to  your  drawing-board  by  pins 
or  springs ;  alongside  of  it  a  half-sheet  of  fine 
glazed  paper  for  the  wheel  of  the  instrument  to  move 
on.  Place  the  needle-point  A  at  a  proper  point  on 
the  paper  and  the  tracer  B  on  a  marked  point  of  the 
outline  of  diagram  D;  then  raise  the  wheel  C  and 
turn  it  until  0  on  the  cylinder  corresponds  with  0 
on  the  vernier  E,  press  lightly  with  a  finger  of  the 
left  hand  on  the  point  A,  and  with  the  fingers  of  the 
right  hand  take  hold  of  the  top  of  the  tracer  B,  and 
carefully  follow  the  line  in  the  direction  of  the  hands 
of  a  watch  until  it  reaches  the  starting-point.  WTe 
now  read  the  instrument.  We  find  that  0  on  the 
cylinder  has  passed  on  from  0  on  JS9  and  2  has  passed 
it.  We  write  2  (2  inches).  We  follow  it  by  seeing 
how  much  2  has  passed.  We  find  it  shows  four 
marks  on  the  cylinder  and  a  little  more.  We  write 


172  AMSLER'S    POLAR-PLANIMETER. 

4,  which  is  r%.  We  now  look  for  a  mark  on  the 
cylinder  that  corresponds  with  one  on  the  Vernier  E. 
In  this  case  we  find  the  second  mark  from  Vernier  0 
corresponds  with  a  mark  on  the  cylinder.  We  write 
2,  being  Tf 7.  The  reading  then  is  thus,  2.42  square 
inches,  area  of  diagram.  We  now  measure  the  length 
of  the  diagram  in  inches,  parallel  to  the  atmospheric 
line,  which  in  this  case  is  four  inches.  We  now  divide 
the  area  by  the  length  ;  the  quotient  is  the  mean 
height  in  inches  of  the  diagram,  which  is  .605  inches  ; 
this  we  multiply  by  the  scale  of  the  indicator,  which 
is  thirty  to  the  inch  in  this  case  ;  the  product  gives 
us  18.15  Ibs.  mean  pressure  on  each  square  inch  of 
the  piston.  The  sum  is  thus  : 

4  )  2.42 
.605 

30 

18.150  Ibs.,  mean  pressure. 
Expressed  thus  : 

2.42  -f-  4  =  .605  x  30  =  18.15. 

N.  B. — If  the  diagram  should  measure  more  or 
less  than  four  inches  in  length,  divide  by  what  it 
may  be ;  so  also  with  the  indicator  scale,  multiply 
by  what  it  is. 

If  the  figure  to  be  measured  is  a  plan  drawn  to  a 
scale,  we  proceed  as  above  to  get  the  square  inches  ; 
we  find  in  this  case  the  reading  to  be  nine  square 
inches,  our  scale  is  one  inch  to  one  foot,  which  is 


AMSLER'S  'POLAR    PLANIMETER.  173 

one-twelfth  size  ;  to  raise  this  to  full  size,  we  multi- 
ply the  reading  by  the  square  of  the  ratio,  thus  : 
12  x  12  =  144  x  9  =  1296  square  inches'  full  size. 
Same  in  all  other  scales.  Square  the  denominator  and 
multiply  the  product  by  the  reading ;  the  product  is 
full  size  in  square  inches. 

In  giving  in  the  foregoing  direction  how  to  read 
the  record  of  the  instrument,  we  have  supposed  that 
the  operator  was  not  familiar  with  the  Vernier  scale, 
hence  we  advised  him  to  put  0  and  0  to  correspond  ; 
this  is  right,  though  not  necessary. 

FOR  EXAMPLE  :  The  instrument  is  in  place,  the 
reading  is  1.14,  the  tracer  is  carried  around  the  out- 
lines as  directed,  and  the  reading  is  3.56  ;  now  we 
subtract  the  first  reading  from  the  second,  thus  : 

3.56  -  1.14  =  2.42  3.56 

1.14 
2~42 

This  the  learner  will  soon  get  familiar  with. 

THE    CARE    OF    THE    INSTRUMENT. 

It  is  exceedingly  delicate  ;  it  will  not  bear  banging 
like  a  horse-shoe,  nor  suffered  to  become  foul.  Care 
must  be  taken  that  £he  roller-wheel  revolves  perfectly 
free  end  yet  no  looseness  in  its  'pivots,  the  same  in  all 
the  joints.  Take  great  care  that  the  roller-wheel 
and  vernier-scale  don't  get  msty  or  foul  with  dirt. 
Oil  the  movable  points  with  porpoise  oil  and  none 


174 


AMSLER  S    POLAR-PLAIslMETER. 


other.  It  can  always  be  procured  at  the  watch  or 
clock  maker's.  This  is  imperative,  if  correct  results 
are  to  be  attained. 

The  above  description  is  believed  to  be  sufficient 
for  all  practical  purposes.  For  a  mathematical  ex- 
position, disclosing  the  scientific  principles  on  which 
it  acts,  see  Spon's  Dictionary. 

For  convenience  in  using  the  common  rule  to 
measure  the  length  of  the  diagram,  we  have  calcu- 
lated the  following  table,  reducing  the  common 
fraction  to  decimals  : 


Com. 
Prac. 

Decimal.) 

Com. 
Frac. 

Decimal. 

Com. 
Frac. 

Decimal. 

Com. 
Frac. 

Decimal. 

A 

.0312 

A 

.2812 

H 

.5312 

« 

.7812 

yV 

.0625 

A 

.3125   tV 

.5625 

ft 

.8125 

A 

.0937 

H 

.3437 

H 

.5977 

H 

.8437 

t 

.1250 

t 

.3750 

1 

.6250 

i 

.8750 

A 

.1562 

if 

.4062 

H 

.6562 

« 

.9062 

A 

.1875 

A 

.4375 

•H 

.6875 

H 

.9375 

A 

.2187 

•H 

.4687 

If 

.7187 

« 

.9687 

i 

.2500 

i 

.5000 

f 

.7500 

It 

1.0000 

From  the  above  description  and  examples  it  will 
be  seen  that  calculating  the 'diagram  is  reduced  to 
the  minimum  of  time  and  maximum  of  accuracy. 
We  dispense  with  the  use  of  the  parallel  rule,  with 


AMSLER'S   POLAE-PLANIMETEB.  175 

ten  or  more  measurements,  with  adding  up  a  long 
column  of  figures  and  the  required  divisions,  to  get 
a  doubtful  result  at  best,  and  substitute  the  described 
manipulation  of  the  instrument ;  note  its  reading, 
and  by  the  use  of  fourteen  figures  get  a  positively 
accurate  result. 

DIRECTIONS. 

Before  taking  the  diagram,  shut  off  the  supply  of 
whatever  lubricant  is  used  in  the  cylinder  of  the 
engine,  which  is  usually  some  gummy  oil  or  other 
villainous  compound,  that  gums  the  piston  and 
cylinder  of  the  instrument,  rendering  its  action 
dull,  showing  curves  where  there  should  be  angles, 
and  retarding  its  free  action  generally. 

Oil  the  piston  of  the  instrument  often  when  in  use, 
and  see.  that  the  cylinder  is  smooth  and  clean,  for 
on  these  points  depend  largely  the  integrity  of  its 
action  and  correctness  of  the  diagrams. 

TO  SELECT  A  SPRING  FOR  A  GIVEN  PRESSURE. 

RULE. — Divide  the  boiler  pressure  by  2.5;  th© 
quotient  is  the  proper  number  of  spring. 

EXAMPLE.— Boiler  pressure,  75  Ibs.  -f-  2.5  =  30. 

It  is  good  practice  to  use  as  low  number  as  will  do 
for  the  pressure,  so  as  to  get  the  diagram  on  a  large 
scale. 


INDEX  TO  SUPPLEMENT. 


PAGE 

Diagram  No.  1. — Showing  the  Action  of  the  Instrument, 

Thompson's  Indicator 160-161 

Diagram  No.  2. — With  Explanation  of  the  "  loop  below,"  162 

How  to  Treat  it 163 

Diagram  No.  3.— Its  Character 165 

Kule  for  Reducing  Motion  of  Piston  to  required  Length 

of  Diagram 167 

Indicator  Pantograph 168 

Amsler's  Polar-Plani meter  with  Cut 168-169 

Description  of  the  Instrument 170 

How  to  Use  it 171 

Examples 172-173 

Care  of  the  Instrument 173-174 

Table  for  Reducing  Common  Fractions  to  Decimals 174 

Directions 175 

How  to  Select  a  Spring  for  a  Given  Pressure 175 


INDEX. 


PAGB 

American  Editor's  Preface 7 

Nature  and  Use  of  the  Indicator. 9 

Mode  of  proceeding  to  Find  the  Power  a  Tenant  Uses. .  9 

Analysis  of  Diagram  No.  1 14 

Truth  of  the  Diagram 16 

Conditions  of  a  Correct  Diagram . . . 16 

Errors  Liable 17 

General  Construction  of  the  Indicator 18 

Metallic  Pencil 19 

List  of  Springs 20 

Practical  Directions  for  Applying  and  Taking  Care  of  the 

Indicator 21 

Giving  Motion  to  the  Paper 24 

From  what  Points  to  Derive  the  Motion 25 

"                "•               "                 "         on  Locomotves. .  27 

on  Oscillating  En- 
gines    28 

How  to  Take  a  Diagram 29 

To  Connect  the  Cord 30 

To  Take  the  Diagram 31 

Notes  on  Diagram 33 

How  to  Keep  the  Indicator  in  Order 34 

Note  on  the  Importance  of  Proper  Oil 34 

How  to  Change  the  Springs 36 

"             Barrel  Springs 36 

1 '        Ascertain  the  Power  Exerted  by  the  Engine ...  37 

On  Diagrams  from  Condensing  Engines 40 

177 


INDEX. 

PAGE 

Power  Exerted  by  Engines  as  Per  Diagram  No.  1,  with 

Example 43 

On  Diagrams  from  Non-condensing  Engines — Example. .     46 
To  Measure  from  the  Diagram  the  Amount  of  Steam 

Consumed 49 

Observations  on  the  Several  Lines  of  the  Diagram 51 

Classifications  of  Engines,  Steam  Line 52 

Full  Stroke,  Lap,  Link,  Independent,  by  Action  of  Gover- 
nor on  the  Cut-off  Valve,  and  according  to  the  Work 

by  Throttle 52,  53 

Prof.  Tyndall's  Experiments 57 

Importance  of  Cutting-off  quickly 60,  61 

To  find  Mean  Pressure  by  Hyperbolical  Logarithms.    . .       62 

Remarks  of  the  Editor — Examples 68,  64 

Exhaust  Line  and  Line  of  Counter  Pressure 64 

Compression  Line 65 

Theoretic  Curve  and  its  Uses ;  How  it  is  made  ;  Clear- 
ance Defined 67,  68 

Cards  from  a  Caloric  Engine 72 

Trip  from  Wilmington  to  Philadelphia  on  Locomotive 

No.  50,  with  Method  of  Operation 73 

Valve  Setting— How  to  set  a  Slide  Valve 78 

Remarks  on  Table  V. — How  to   find  if  the   Engine  is 
tight,  and  how  to  find  the  Clearance 94 


TA.BLES. 


Table  No.  I.— Areas  of  Circles 81 

Circumferences  of  Circles 86 

Table  No.  II.— Showing  Weight  of  the  Atmosphere  at 

different  Heights  of  the  Barometer 89 

Table  reducing  common  fractions  to  decimals 174 


INDEX.  179 

PAGE 

Table  No.  III.— Showing  the  Elastic  Force  of  Steam  at 

Different  Temperatures 90 

Table  No.  IV. —Logarithms 92 

Table  No.  V. — Steam  Used  Expansively.     Average  Pres- 
sure in  Ibs.  per  square  inch  for  the  Whole  Stroke. . .     93 

Diagrams 97-143 

Diagram  No.  1. — Supplement 161 

"  2.—  "         164 

"  3.—  "  .  166 


Cement  for  Steam  Joints 145 

A  Good  Dressing  for  Leather  Belts 146 

Rules  for  Calculating  Belting 146 

How  to  Make  Belts  run  on  Centres  of  Pulleys 148 

"Idlers" 149 

Measuring  Steam  used  for  Heating   149 

Condensation  of  Pipes  and  Coils . .  149 

Radiating  Surface  of  Steam-pipe  required  to  Heat  Build- 
ings and  Apartments .    148 

Comparative  Value  of  Pea  and  Dust  Coal  with  Lump 152 

"          Cumberland  and  Anthracite 152 

Cleaning  Gauge  of  Glasses 152 

Extraordinary  Corrosion 152 

To  Ascertain  if  Iron  is  in  Solution  153 

Quantity  of  Steam  to  Heat  a  Given  Quantity  of  Water. .  153 

Farbairn's  Experiment  on  Boiler  Flues 153 

Dressing  for  Emery  Wheels 153 

To  Cool  Hot  Bearings 154 

Scale  in  Boilers 154 

Lime  is  Suspected.     Test 154 

Rule  for  Calculating  Horse-powers  of  Water  .  .^  „ 155 

The  Inspirator ••••.. 155 

Rubber  Steam  Joints (. . T. 155 


ANOTHER  edition,  the  fourth,  of  this  work  is  called  for, 
which  indicates  that  our  working  engineers  are  becoming 
educated  in  the  use  of  the  Indicator  to  their  great  advantage 
and  the  interest  of  their  employers,  who,  as  a  rule,  appreciate 
the  great  advan- 
tages made  man- 
ifest and  tangi- 
ble by  its  intelli- 
gent use.  Com- 
bined with  the 
Fairbanks  Scale 
it  shows  them 
unerringly  how 
much  power  they 
get  for  a  dollar 
from  the  various 
kinds  of  fuels  in 
use. 

In  our  third 
edition,  page  168, 
we  noted  the 
pantograph, 
which  is  now  in 
general  use, 
which  is  shown 
in  the  engraving. 
It  is  shown  to  be 
connected  with 
the  old-style  hor- 
izontal cross- 
head,  links  held 
fast  by  the  lock- 
nut  of  the  gib 

adjusting  screw.  THE  PANTOGRAPH. 

It  will  be  seen  that  the  link  is  by  its  joints  capable  of  being 
expanded  or  contracted  in  its  opening  from  0  to  3)£",  §g 


that  it  will  embrace  the  largest  Corliss  vertical  crosshead  to 
the  smallest  adjusting  or  other  screw.  There  are  some  small 
pieces  go  with  it,  to  adjust  and  attach  it,  which  the  engineer 
will  at  once  see  the 
use  of  in  its  applica- 
tion under  the  va- 
rious kinds  of  en- 
gines and  positions 
he  finds  them.  We 
have  never  seen  an 
engine  that  we  could 
not  get  an  attach- 
ment with  it  in  ten 
minutes.  This  link 
attachment  is  a 
small,  simple  affair, 
can  be  carried  in 
the  pocket,  and  is 
equally  convenient 
and  useful  with  the 
ordinary  mode  of 
reducing  the  motion 
as  with  the  panto- 
graph. The  link  at- 
tachment is  applic-* 
able  to  all  engines — 
horizontal,  vertical, 
inclined-rotary,  or 
oscillating.  It  is 
known  as  BACON'S 
PATENT  PANTO- 
GRAPH ATTACHMENT. 
Notwithstanding 
the  facilities  fur- 
nished by  the  above 
attachment  in  get- 
ting the  motion 
from  the  crosshead 
or  other  proper 
point,  still  another 
difficulty  often  oc- 
curs which  gives  us 
more  or  less  trouble 
to  manage,  and  that  is  to  lead  the  line  off  in  the  proper  direc- 
tion so  as  to  give  a  correct  result.  Steam-pipes,  exhaust-pipe^ 


and  other  obstructions  incident  to  the  structure  of  the  engine, 
often  the  contracted  space  allotted  to  it,  and  unforeseen  awk- 
ward conditions  oft- 
en with  the  old  ar- 
rangement,, render  it 
impossible  to  get  the 
line  to  run  parallel 
with  the  piston-rod 
(a  sine  qua  non) 
without  too  many 
carrying  pulleys  or 
chafing  the  lines, 
which  must  in  any 
event  be  avoided  if 
we  would  have  cor- 
rect results.  Hap- 
pily the  patentee  has 
helped  us  out  of  this, 
as  the  accompanying 
cats  will  show. 

Fig.  1  shows  the 
original  Thompson 
instrument.  1A 
shows  the  swivel- 
base  and  carrying- 
pulleys.  This  'base 
can  swivel  around  to 
the  right  or  left,  but 
the  pulleys  remain 
upright,  which  is 
sometimes  exceed- 
ingly inconvenient. 

The  improved 
swivel-base  is  shown 
attached  in  Fig  2, 
and  detached  in  Fig. 
2B. 

It  will  be  seen  that 
by  its  construction 
a  swivel  of  itself, 
which  can  be  set  and 
held  by  the  thumb- 
screw at  any  angle 
to  suit  the  line  and  give  it  a  proper  direction  without  dis- 
torting the  diagram  or  abraiding  the  line. 


F.  W.  BACON,  M.  E., 


FURNISHES    INSRUMENTS, 
AND  GIVES  INSTRUCTION  IN  THEIR  USE. 


MANUFACTURERS,  and  others  using  Steam-Engines,  can,  by  apply- 
ing the  INDICATOR,  ascertain  the  condition  of  their  Engines  ;  the 
power  required  to  do  their  work,  or  any  portion  thereof  ;  the  economy 
of  fuel  expended,  when  compared  with  power  developed. 

The  undersigned  makes  a  specialty  of  this  branch  of  engineering, 
and  will  wait  on  any  party  who  desire  his  services. 

Special  attention  given  to  the  erection  of  Steam-Engines  and 
Machinery,  Shafting  and  Belting. 

Will  attend  to  laying  out  works,  and  make  plans  and  estimates. 

Parties  wishing  to  burn  shavings,  saw-dust,  and  other  light  fuels, 
can  have  their  furnaces  constructed  so  as  to  consume  the  smoke  and 
gases  therefrom,  at  a  moderate  cost. 

F.  W.  BACON,  Consulting  Engineer, 

33  Bromfield  Street,  Boston. 


AGENT  FOR 

HANCOCK'S  STEAM  BLOWER, 

The  cheapest,  best,  and  most  efficient 
Blower  known. 

NO  OILING,  NO  SHAFTING,  NO  PULLIES,  NO  BELTING 
^QV_J^  REQUIRED. 

For  burning  screenings,  re-heating  in  rolling  mills,  and  hot  nut- 
presses  it  has  no  substitute. 

Guaranteed  to  give  entire  satisfaction  or  no  sale. 


Lane's  Improvement— Inside  View. 


ORIGINAL  STEAM  GAUGE  Co.— BUSINESS  ESTABLISHED  IN  1851. 
INCORPORATED  IN  1854. 


SOLE  MANUFACTURERS   OF  THE 

THOMPSON   IMPROVED  INDICATOR. 


THE  THOMPSON   IMPROVED   INDICATOR. 

BOURDON    STEAM    GAUGE, 

WITH  LANE'S  IMPROVEMENT. 

Amsler's  Polar  Planimeter  and  the  Pantograph, 

36  Cliardon   Street,  Boston,  Mass. 

J.  C.  BIAISDELL,       E.  BtRT  PHILIIPS,       H.  K.  MOOBE, 
Pres.  Treas.  Supt, 


FOR 


ELECTRIC  LIGHTING  UNEQUALLED. 


FOR  OTHER  PURPOSES  UNEXCELLED. 


PATENT  STEM  PUMPS 

THE   STANDARD! 


SEND  FOR   CATALOGUE. 


ADDRESS 


Knowles  Steam-Pump  Works, 

44  Washington  Street,  Boston,  Mass, 

93  Liberty  Street,  New  York, 


TED  STEAM  PUMPS, 


PUMPING  MACHINERY 

OF   EVERY    DESCRIPTION. 


Send  for  New  Illustrated  Catalogue. 


GEO.  F.  BLAKE  M'FG  CO., 

95  &  97  Liberty  Street,  New  York. 

44  Washington  Street,  Boston,  Mass, 


JAftYIS  PATENT  FUBNACE 

FOR    SETTING 

STEA.M  BOILERS. 


Economy  of  Fuel,  with  increased  capacity  of  steam-power.  Like  the 
SIEMENS  STEEL  PROCESS,  it  utilizes  the  waste  gases  with  hot  air  on 
top  of  the  fire.  Burns  all  kinds  of  waste  without  a  blast,  including  screen- 
ings, wet  peat,  wet  hops,  sawdust,  logwood  chips,  slack  coal,  wet  oagasse, 
etc.  Send  for  circular. 

JARVIS    ENGINEERING  CO., 

A.  F.  UPTON,  TREASURER, 

7  Oliver  Street,  Boston,  Mass. 


OVER   50,000    IN    USE. 


THE  BEST  FEEDER  KNOWN   FOR 

STATIONARY,  MARINE, 

AND  LOCOMOTIVE  BOILERS. 


AWARDED    A 

IMC 

THE    HIGHEST    PRIZE, 

At  the   Paris   Exposition,   1878, 


CONSUMES  LESS  STEAM  THAN  ANY 
OTHER  BOILER  FEEDER  KNOWN. 


It  is  the  Injector  Perfected. 


ALLSIZES  LIFT  WATER 
25  FEET. 


NO    ADJUSTMENT    REQUIRED    FOR 
VARYING  STEAM  PRESSURES. 


BOILERS  LAST  LONGER 

AND  STEAM  BETTER 
WITH  THE    INSPIRATOR 

THAN    WITH    A    PUMP. 
Manufactured  by  the 

HANCOCK    INSPIRATOR    CO., 

34    BEA^OTtC    STREET, 
BOSTON,    MASS. 

jEEi>T  VICTOR.I-A-  STREET, 
LONDON,   ENG-. 


Organised  1366. 


J.  M.  ALLEN,  President. 

W.  B.  FRANKLIN,  J.  B.  PIERCE, 

Vice-President.  Secretary. 


1852. 


J.  H,  &  T,  CUNNINGHAM,  Proprietors, 


MANUFACTURERS  OF 


BOSTON,    MASS. 

OFFICE,  WAREHOUSE, 

At  Works,  Charlestown,  Mass.         No.  109  Milk  Street,  Boston. 


MANUFACTURERS  OF 


Turret,  Screw-Chasing- 

HAND   LATHES, 

CHUCKS,   AND  SLIDE-RESTS. 

OF  ALL  SIZES, 

VALVE  MILLING   MACHINES,   SHAFTING, 
HANGERS,  AND  PULLEYS, 

No.    84  KING-STON   STREET 
BOSTON,  MASS. 

BENJ.  F.  RADFORD,  Supt.  CHAS.  R.  MCLEAN,  Treas. 


BOSTON,  MASS. 

1854. 


SOLE   MANUFACTURERS   OF 


'I 

WITH 

LANE'S    IMPROVEMENT. 

— 

WATER  GAUGES, 

COMPOUND  GAUGES, 

HYDEAULIC  GAUGES, 

COMBINATION  GAUGES, 

VACUUM  GAUGES, 
MERCURIAL  SIPHON  GAUGES. 

Also  exclusive  Manufacturers  of 

THOMPSON  IMPROVED  and  RICHARDS  STEAM- 
ENGINE  INDICATORS, 

GAUGE  COCKS, 

LONG'S  SALINOMETER  POTS, 

PYROMETERS,  HYDROMETERS, 

HIGH  AND  LOW  GRADE  THERMOMETERS, 

SALINOMETER  THERMOMETERS, 

LANE'S  LOW- WATER  AND  ALARM  GAUGES, 

CLOCKS,  REVOLUTION  COUNTERS, 

HUSSEY  SPEED  INDICATORS, 

MERCURY  COLUMNS, 

And  all  kinds  of 

STEAMSHIP  INSTRUMENTS. 


Established   1864. 


WILLIAM  A.  HARRIS, 


MANUFACTURER   OF 


WITH 


mm  rmnm  niriovsinin. 


ALSO 

HEAVY  AND  LIGHT 


IRON  AND  BRASS  CASTINGS, 


R.  I. 


'»*  Any  book  in  this  Catalogue  sent  free  by  mail  on  receipt  of  price, 

VALUABLE 

SCIENTIFIC    BOOKS 

PUBLISHED   BY 

D.  VAN  NOSTRAND, 

23  MURRAY  STREET  AND  27  WARREN  STREET,  N.  Y. 


ADAMS  (J.  W.)  Sewers  and  Drains  for  Populous  Districts. 
Embracing  Rules  and  Formulas  for  the  dimensions  and 
construction  of  works  of  Sanitary  Engineers.  Second  edi- 
tion. 8vo,  cloth $2  50 

ALEXANDER  (J.  H.)  Universal  Dictionary  of  Weights  and 
Measures,  Ancient  and  Modern,  reduced  to  the  standards 
of  the  United  States  of  America.  New  edition,  enlarged. 
8vo,  cloth 3  50 

ATWOOD(GEO.)    Practical  Blow-Pipe  Assaying.  12010,  cloth, 

illustrated 2  oo 

AUCHINCLOSS  (W.  S.)  Link  and  Valve  Motions  Simplified. 
Illustrated  with  37  wood-cuts  and  21  lithographic  plates, 
together  with  a  Travel  Scale  and  numerous  useful  tables. 
8vo,  cloth  300 

AXON  (W  E.  A.)  The  Mechanic's  Friend  :  a  Collection  of  Re- 
ceipts and  Practical  Suggestions  Relating  to  Aquaria — 
Bronzing— Cements— Drawing— Dyes— Electricity— Gilding 
— Glass-working  —  Glues  —  Horology  —  Lacquers  —Locomo- 
tives—Magnetism— Metal-working  -  Modelling  —  Photogra- 
phy— Pyrotechny— Railways— Solders— Steam-Engine—Tel- 
egraphy— Taxidermy—  Varnishes— Waterproofing,  and  Mis- 
cellaneous Tools,  Instruments,  Machines,  and  Processes 
connected  with  the  Chemical  and  Mechanic  Aits.  With  nu- 
merous diagrams  and  wood-cuts.  Fancy  cloth  15° 

BACON  (F.  W.)  A  Treatise  on  the  Richards  Steam-Engine 
Indicator,  with  directions  for  its  use.  Hv  Charles  T.  Por- 
ter. Revised,  with  notes  and  large  additions  as  developed 
by  American  practice  ;  with  an  appendix  containing  useful 
formula  and  rules  for  engineers.  Illustrated.  Third  edi- 
tion. I2mo,  cloth I  oo 


2  D.    VAN   NOSTRAND  S   PUBLICATIONS. 

BARBA  (J.)  The  Use  of  Steel  for  Constructive  Purposes  : 
Method  of  Working,  Applying,  and  Testing  Plates  and 
Brass.  With  a  Preface  by  A.  L.  Holley,  C.E.  I2mo,  cloth.$i  50 

BARNES  (Lt.  Com.  J.  S.,  U.  S.  N.)  Submarine  Warfare,  offen- 
sive and  defensive,  including  a  discussion  of  the  offensive 
Torpedo  System,  its  effects  upon  Iron-Clad  Ship  Systems 
and  influence  upon  future  naval  wars.  With  twenty  litho- 
graphic plates  and  many  wood-cuts.  8vo,  cloth 5  oo 

BEILSTEIN  (F.)     An  Introduction  to  Qualitative  Chemical 

Analysis,  translated  by  I.  J.  Osbun.    I2mo,  cloth 75 

BENET  (Gen.  S.  V.,  U.  S.  A.)  Electro-Ballistic  Machines,  and 
the  Schultz  Chronoscope.  Illustrated.  Second  edition,  410, 
cloth 3  oo 

BLAKE  (W.  P.)  Report  upon  the  Precious  Metals  :  Being  Sta- 
tistical Notices  of  the  principal  Gold  and  Silver  producing 
regions  of  the  World;  represented  at  the  Paris  Universal 
Exposition.  8vo,  cloth 2  oo 

Ceramic  Art.  A  Report  on  Pottery,  Porcelain,  Tiles, 

Terra  Cotta,  and  Brick.  8vo,  cloth 2  oo 

BOW  (R.  H.)  A  Treatise  on  Bracing,  with  its  application  to 
Bridges  and  other  Structures  of  Wood  or  Iron.  156  illustra- 
tions. 8vo,  cloth i  V) 

BOWSER  (Prof.  E.  A.)  An  Elementary  Treatise  on  Analytic 
Geometry,  embracing  Plane  Geometry,  and  an  Introduc- 
tion to  Geometry  of  three  Dimensions.  I2mo,  cloth i  75 

— — —  An  Elementary  Treatise  on  the  Differential  and  Integral 

Calculus.  With  numerous  examples.  I2mo,  cloth 2  25 

BURGH  (N.  P.)  Modern  Marine  Engineering,  applied  to  Pad- 
dle and  Screw  Propulsion.  Consisting  of  36  colored  plates, 
259  practical  wood-cut  illustrations,  and  403  pages  of  de- 
scriptive matter,  the  whole  being  an  exposition  of  the  pre- 
sent practice  of  James  Watt  &  Co.,  J.  &  G.  Rennie,  R.  Na- 
pier &  Sons,  and  other  celebrated  firms.  Thick  410  vol., 

cloth 1000 

Half  morocco 15  oo 

BURT  (W.  A.)  Key  to  the  Solar  Compass,  and  Surveyor's  Com- 
panion ;  comprising  all  the  rules  necessary  for  use  in  the 
field :  also  description  of  the  Linear  Surveys  and  Public 
Land  System  of  the  United  States,  Notes  on  the  Barome- 
ter, suggestions  for  an  outfit  for  a  survey  of  four  months, 
etc.  Second  edition.  Pocket-book  form,  tuck 2  50 

BUTLER  (Capt.  J.  S.,  U.  S.  A.)  Projectiles  and  Rifled  Cannon. 
A  Critical  Discussion  of  the  Principal  Systems  of  Rifling 
and  Projectiles,  with  Practical  Suggestions  for  their  Im- 
provement, as  embraced  in  a  Report  to  the  Chief  of  Ord- 
nance.U.S.A.  s6plates.  410,  cloth 6  oo 


D.  VAN  NOSTRAND'S  PUBLICATIONS. 


CAIN  (Prof.  WM.)    A  Practical  Treatise  on  Voussoir  and  Solid 

and  Braced  Arches.    i6mo,  cloth  extra  ....................  $i  75 

CALDWELL  (Prof.  GEO.  C.)  and  BRENEMAN  (Prof.  A.  A.) 
Manual  of  Introductory  Chemical  Practice,  for  the  use  of 
Students  in  Colleges  and  Normal  and  High  Schools.  Third 
edition,  revised  and  corrected.  8vo,  cloth,  illustrated.  New 
and  enlarged  edition.  ..  ...................................  i  50 

CAMPIN  (FRANCIS).    On  the  Construction  oflron  Roofs.  8vo, 

with  plates,  cloth  ...........  .  ..............................  2  oo 

CHAUVENET  (Prof.  W.)  New  method  of  correcting  Lunar 
Distances,  and  improved  method  of  finding  the  error  acnd 
rate  of  a  chronometer,  by  equal  altitudes,  8vo,  cloth  ......  2  OO' 

CHURCH  (JOHN  A.)    Notes  of  a  Metallurgical  Journey  in 

Europe.     8vo,  cloth  .......................................  2  o»« 

CLARK  (D.  KINNEAR,  C.E.)  Fuel:  Its  Combustion  and 
Economy,  consisting  of  Abridgments  of  Treatise  on  the 
Combustion  of  Coal  and  the  Prevention  of  Smoke,  by  C. 
W.  Williams  ;  and  the  Economy  of  Fuel,  by  T.  S.  Pri- 
deaux.  With  extensive  additions  on  recent  practice  in  the 
Combustion  and  Economy  of  Fuel  :  Coal,  Coke,  Wood, 
Peat,  Petroleum,  etc.  I2mo,  cloth  .........................  I  50-- 

-  A   Manual  of  Rules,  Tables,   and  Data  for  Mechanical 
Engineers.  Based  on  the  most  recent  investigations.     Illus- 
trated with  numerous  diagrams.     1,012  pages.    8vo,  cloth...  7  50 
Halfmorocco  .............................................  10  oo 

CLARK  (Lt.  LEWIS,  U.  S.  N  )  Theoretical  Navigation  and 
Nautical  Astronomy.  Illustrated  with  41  wood-cuts.  8vo, 
cloth  ......................................................  I  50- 

CLARKE  (T.  C.)  Description  of  the  Iron  Railway  Bridge  over 
the  Mississippi  River  at  Quincy,  Illinois.  Illustrated  with 
21  lithographed  plans.  4to,  cloth  ..........................  7  y> 

CLEVENGER  (S.  R.)  A  Treatise  on  the  Method  of  Govern- 
ment Surve>ing,  as  prescribed  by  the  U.  S.  Congress  and 
Commissioner  of  the  General  Land  Office,  with  complete 
Mathematical,  Astronomical,  and  Practical  Instructions  for 
the  use  of  the  United  States  Surveyors  in  the  field.  i6mo, 
morocco  ....................................................  2  y>' 

COFFIN  (Prof.  J.  H.  C  )  Navigation  and  Nautical  Astrono- 
my. Prepared  for  the  use  of  the  U.  S.  Naval  Academy. 
Sixth  edition.  52  wood-cut  illustrations.  I2mo,  cloth  ......  3  y>- 

COLBURN   (ZERAH).     The  Gas-Works  of   London.     I2mo, 

boards  .....................................................      6o>- 

COLLINS  (JAS.  E.)    The  Private  Book  of  Useful  Alloys  and 

Memoranda  for  Goldsmiths,  Jewellers,  etc.     i8mo,  cloth...      50- 


4  D.    VAN   NOSTRAND  S   PUBLICATIONS. 

CORNWALL  (Prof.  H.  B.)  Manual  of  Blow-Pipe  Analysis, 
Qualitative  and  Quantitative,  with  a  Complete  System  of 
Descriptive  Mineralogy.  8vo,  cloth,  with  many  illustra- 
tions. N.  Y.,  1882 $250 

(B.  F.)  Weights  and  Measures.  An  account  of  the 
Decimal  System,  with  Tables  of  Conversion  for  Commer- 
cial and  Scientific  Uses.  Square  32me,  limp  cloth 50 

CRAIG  (Prof.  THOS.)    Elements  of  the  Mathematical  Theory 

of  Fluid  Motion.     i6mo,  cloth 125 

DAVIS  (C.  B.)  and  RAE  (F.  B.)  Hand-Book  of  Electrical  Dia- 
grams and  Connections.  Illustrated  with  32  full-page  illus- 
trations. Second  edition.  Oblong  8vo,  cloth  extra 200 

D1EDRICH  (JOHN).  The  Theory  of  Strains  :  a  Compendium 
.  lor  the  Calculation  and  Construction  of  Bridges,  Roofs,  and 
Cranes  Illustrated  by  numerous  plates  and  diagrams. 
8vo,  cloth 5  00 

£>IXON  (D.  B.)  The  Machinist's  and  Steam-Engineer's  Prac- 
tical Calculator.  A  Compilation  of  useful  Rules,  and  Prob- 
lems Arithmetically  Solved,  together  with  General  Informa- 
tion applicable  to  Shop-Tools,  Mill-Gearing,  Pulleys  and 
Shafts,  Steam-Boilers  and  Engines.  Embracing  Valuable 
Tables,  and  Instruction  in  Screw-cutting,  Valve  and  Link 
Motion,  etc.  i6mo,  full  morocco,  pocket  form  .  ..(In  press) 

DODD  (GEO.)  Dictionary  of  Manufactures,  Mining,  Ma- 
chinery, and  the  Industrial  Arts .  I2tno,  cloth i  50 

DOUGLASS  (Prof  3.  H.)  and  PRES.COTT(Prof.  A  B.)  Qual- 
itative Chemical  Analysis.  A  Guide  in  the  Practical  Study 
of  Chemistry,  and  in  the  Work  of  Analysis.  Third  edition. 
8vo,  cloth 3  50 

DUBOIS  (A.  J[.)    The  New  Method  of  Graphical  Statics.  With 

60  illustrations.    8vo,  cloth i  tp 

EASSIE  (P.  B.)  Wood  and  its  Uses.  A  Hand-Book  for  the  use 
of  Contractors,  Builders,  Architects,  Engineers,  and  Tim- 
ber Merchants.  Upwards  of  250  illustrations.  8vo,  cloth.  150 

EDDY  (Prof.  II.  T.)  Researches  in  Graphical  Statics,  embrac- 
ing NewConstructionsin  Graphical  Statics,  a  New  General 
Method  in  Graphical  Statics,  and  the  Theory  of  Internal 
Stress  in  Graphical  Statics.  8vo,  cloth I  y> 

ELIOT  (Prof.  C.  W.)  and  STOKER  (Prof.  F.  H.)  A  Compen- 
dious Manual  of  Qualitative  Chemical  Analysis.  Revised 
with  the  co-operation  of  the  authors.  By  Prof.  William  R. 
Nichols.  Illustrated.  I2mo,  cloth i  50 

ELLIOT  (Maj.  GEO.  H.,  U.  S.  E.)  European  Light-House 
Systems .  Being  a  Report  of  a  Tour  of  Inspection  made  in 
1873.  51  engravings  and  21  wood-cuts.  8vo,  cloth 5  oo 


D.  VAN  NOSTRAND'S  PUBLICATIONS.  5 

ENGINEERING  FACTS  AND  FIGURES.  An  Annual 
Register  of  Progress  in  Mechanical  Engineering  and  Con- 
struction for  the  years  1863-64-65-66-67-68.  Fully  illus- 
trated. 6  vols.  i8mo,  cloth  (each  volume  sold  separately), 
per  vol  ......................................................  $2  50 

FANNING  (J.  T.)  A  Practical  Treatise  of  Water-Supply  En- 
gineering. Relating  to  the  Hydrology,  Hydrodynamics,  and 
Practical  Construction  oi  Water-Works  in  North  America. 
Third  edition.  With  numerous  tables  and  180  illustra- 
tions. 6sopages.  8vo,  cloth  ..............................  500 

FISKE  (BRADLEY  A.,  U.  S.  N.)  Electricity  in  Theory  and 
Practice.  8vo,  cloth  ..............................  (In  press) 

FOSTER  (Gen.  J.  G.,  U.  S.  A  )  Submarine  Blasting  in  Boston 
Harbor,  Massachusetts.  Removal  oi  Tower  and  Corwin 
Rocks.  Illustrated  with  seven  plates.  4to,  cloth  ..........  3  «f> 

FOYE  (Prof.  J.  C.)  Chemical  Problems.  With  brief  State- 
ments of  the  Principles  involved.  Second  edition,  revised 
and  enlarged.  i6mo,  boards  ...........  ...................  5» 

FRANCIS  (JAS.  B.,  CE.)  Lowell  Hydraulic  Experiments: 
Being-  a  selection  from  Experiments  on  Hydraulic  Motors, 
on  the  Flow  of  Water  over  Weirs,  in  Open  Canals  of  Uni- 
form Rectangular  Section,  and  through  submerged  Orifices 
and  diverging  Tubes.  Made  at  Lowell,  Massachusetts. 
Fourth  edition,  revised  and  enlarged,  with  many  new  ex- 
periments, and  illustrated  with  twenty-three  copperplate 
engravings.  4to,  cloth  ....................................  .  15  °» 

FREE-HAND  DRAWING.  A  Guide  to  Ornamental  Figure 
and  Landscape  Drawing.  By  an  Art  Student.  i8mo, 
boards  ......................................................  50 

GILLMORE  (Gen.  Q.  A.)  Treatise  on  Limes.  Hydraulic  Ce- 
ments, and  Mortars.  Papers  on  Practical  Engineering,  U. 
S.  Engimeer  Depaitment,  No.  9,  containing  Reports  of 
numerous  Experiments  conducted  in  New  York  City  during 
the  years  1858  to  1861,  inclusive.  With  numerous  illustra- 
tions. 8vo,  cloth  .........................................  4  oa 

-  Practical  Treatise  on  the  Construction  of  Roads,  Streets, 

and  Pavements.    With  70  illustrations.    I2mo,  cloth  .......  2  oa 

-  Report  on  Strength  of  the  Building  Stones  in  the  United 
States,  etc.    8vo,  illustrated,  cloth  ....................  ----  150- 

-  Coignet  Beton  and  other  Artificial  Stone.    9  plates,  views, 
etc.    evo,  cloth  .............................................  2  9> 

GOODEVE  (T.  M.)    A  Text-Book  on  the  Steam-Engine.    143 

illustrations.    I2mo,  cloth  ................................  2  CXV 


GORDON  (J.  E.  H.)  Four  Lectures  on  Static  Induction. 

cloth.......  ........................................      &> 


D.  VAN  NOSTRANDS  PUBLICATIONS. 


-GRUNER  (M.  I..)  The  Manufacture  of  Steel,  Translated 
from  the  French,  by  I.enox  Smith,  with  an  appendix  on  the 
Bessemet  process  in  the  United  States,  by  the  translator. 
Illust'ated.  8vo,  cloth $3  50 

HALF-HOURS  WITH  MODERN  SCIENTISTS.  Lectures 
and  Essays.  By  Professors  Huxley,  Barker,  Stirling,  Cope, 
Tyndall,  Wallace,  Roscoe,  Huggins,  Lockyer,  Young, 
Mayer,  and  Reed.  Being  the  University  Series  bound  up. 
Witli  a  general  introduction  by  Noah  Porter,  President  of 
Yale  College.  2  vols.  I2mo,  cloth,  illustrated 2  50 

HAMILTON  (VV.  G.)  Useful  Information  for  Railway  Men. 
Sixth  edition,  revised  and  enlarged  562  pages,  pocket  form. 
Morocco,  gilt 200 

HARRISON  (\V.  B.)  The  Mechanic's  Tool  Rook,  with  Prac- 
tical Rules  and  Suggestions  for  Use  of  Machinists,  Iron- 
Workers,  and  others.  Illustrated  with  44  engravings. 
I2mo,  cloth i  50 

HASKINS  (C.  H.)  The  Galvanometer  and  its  Uses.  A  Man- 
ual for  Electricians  and  Students.  Second  edition.  12010, 
morocco i  50 

HENRICI  (OLAUS).  Skeleton  Structures,  especially  in  their 
application  to  the  Building  of  Steel  and  Iron  Bridges.  With 
folding  plates  and  diagrams.  8vo,  cloth I  50 

HEWSON  (WM.)  Principles  and  Practice  of  Embanking 
Lands  from  River  Floods,  as  applied  to  the  Levees  of  the 
Mississippi.  8vo,  cloth 2  oo 

HOLLEY  (ALEX.  L.)  ATreatiseon  Ordnance  and  Armor,  em- 
bracing descriptions,  discussions,  and  professional  opinions 
concerning  the  materials,  fabrication,  requirements,  capa- 
bilities, and  endurance  of  European  and  American  Guns, 
for  Naval,  Sea-Coast,  and  Iron-Clad  Warfare,  and  their 
Rifling,  Projectiles,  and  Breech-Loading;  also,  results  of 
experiments  against  armor,  from  official  records,  with  an 
appendix  referring  to  Gun-Cotton,  Hooped  Guns,  etc.,  etc. 
948  pages,  .493  engravings,  and  147  Tables  of  Results,  etc. 
8vo,  half  roan 1000 

•  Railway  Practice.  American  and  European  Railway 
Practice  in  the  economical  Generation  of  Steam,  including 
the  Materials  and  Construction  of  Coal-burning  Boilers, 
Combustion,  the  Variable  Blast,  Vaporization,  Circulation, 
Superheating,  Supplying  and  Heating  Feed-water,  etc., 
and  the  Adaptation  of  Wood  and  Coke-burning  Engines  to 
Coal-burning  ;  and  in  Permanent  Way,  including  Road-bed, 
Sleepers,  Rails,  Joint-fastenings,  Street  Railways,  etc.,  etc. 
With  77  lithographed  plates.  Folio,  cloth 12  oo 

HOWARD  (C.  R.)  Earthwork  Mensuration  on  the  Basis  of 
the  Prismoidal  Formulae.  Containing  simple  and  labor- 
saving  method  of  obtaining  Prismoidal  Contents  directly 


D.    VAN  NOSTRAND  S   PUBLICATIONS.  7 

from  End  Areas.  Illustrated  by  Examples,  and  accom- 
panied by  Plain  Rules  for  Practical  Uses.  Illustrated.  8vo, 
cloth $1  yf.  \ 

INDUCTION-COILS.  How  Made  and  How  Used.  63  illus- 
trations. i6mo,  boards  5O»  : 

ISHERWOOD  (B.  F.)  Engineering  Precedents  for  Steam  Ma- 
chinery. Arranged  in  the  most  practical  and  useful  manner 
for  Engineers.  With  illustrations.  Two  volumes  in  one. 
8vo,  cloth 250 

JANNETTAZ  (EDWARD).  A  Guide  to  the  Determination  of 
Rocks:  being  an  Introduction  to  Lithology.  Translated 
from  the  French  by  G.  W.  Plympton,  Professor  of  Physical 
Science  at  Brooklyn  Polytechnic  Institute.  I2mo,  cloth I  50 

JEFFERS  (Capt.  W.  N.,  U.  S.  N.)  Nautical  Surveying.  Illus- 
trated with  9  copperplates  and  31  wood-cut  illustrations. 
8vo,  cloth 5  co 

JONES  (H.  CHAPMAN).    Text-Book   of  Experimental    Or- 

ganic  Chemistry  for  Students.    i8mo,  cloth  . .     I  oo- 

JOYNSON  (F.  H.)  The  Metals  used  in  Construction:  Iron, 

Steel,  Bessemer  Metal,  etc.,  etc.  Illustrated.  I2tno,  cloth.  75; 

Designing  and  Construction  of  Machine  Gearing.  Illus- 
trated. 8vo,  cloth 2  oa- 

KANSAS  CITY  BRIDGE  (THE).  With  an  account  of  the 
Regimen  of  the  Missouri  River,  and  a  description  of  the 
methods  used  for  Founding  in  that  River.  By  O.  Chanute, 
Chief-Engineer,  and  George  Morrison,  Assistant-Engineer. 
Illustrated  with  five  lithographic  views  and  twelve  plates  of 
plans.  410,  cloth 6  oo» 

KING  (W.  H.)  Lessons  and  Practical  Notes  on  Steam,  the 
Steam-Engine,  Propellers,  etc.,  etc  ,  for  young  Marine  En- 
gineers, Students,  and  others.  Revised  by  Chief-Engineer 
I.  W.  King,  U.  S.  Navy.  Nineteenth  edition,  enlarged. 
8vo,  cloth 2  oo» 

KIRKWOOD  (JAS.  P.)  Report  on  the  Filtration  of  River 
Waters  for  the  supply  of  Cities,  as  practised  in  Europe, 
made  to  the  Hoard  of  Water  Commissioners  of  the  City  of 
St.  Louis.  Illustrated  by  30  double-plate  engravings.  410, 
cloth 1500? 

LARRABEE  (C.  S.)  Cipher  and  Secret  Letter  and  Telegra- 
phic Code,  with  Hogg's  Improvements.  The  most  perfect 
secret  code  ever  invented  or  discovered.  Impossible  to  read 
without  the  key.  i8mo,  cloth I  00- 


LOCK  (C.  G.),  WIGNER  (G,  W.),  and  HARLAND  (R.  H.) 
Sugar  Growing  and  Refining.  Treatise  on  the  Culture  of 
Sugar-Yielding  Plants,  and  the  Manufacture  and  Refining  of 


Treatise  on  the  Cultur 
lanufacture  and  Refinii  „ 
Cane,  Beet,  and  other  sugars.    8vo,  cloth,  illustrated 12  oo> 


D.  VAN  NOSTRAND'S  PUBLICATIONS. 


"LOCK  WOOD  (THOS.  D.)  Electricity.  Magnetism,  and  Elec- 
tro-Telegraphy. A  Practical  Guide  for  Students,  Operators, 
and  Inspectors.  8vo,  doth  .....................  (In  press) 

LORING  (A.  E.)    A  Hand-Book  on  the  Electro-Magnetic  Tele- 

graph .     Paper  boards  .....................................  $o  50 

Cloth  .................  .  ....................................      75 

Morocco  ..................................................  I  oo 

MACCORD  (Prof.  C.  W  )  A  Practical  Treatise  on  the.Slide- 
Valve  by  Eccentrics,  examining  by  methods  the  action  of 
the  Eccentric  upon  the  Slide-Valve,  and  explaining  the  prac- 
tical processes  of  laying  out  the  movements,  adapting  the 
valve  for  its  various  duties  in  the  steam-engine.  Second  edi- 
tion Illustrated  .  4to,  cloth  ..............................  2  50 

McCULLOCH  (Prof.  R  S.)  Elementary  Treatise  on  the  Me- 
chanical Theory  of  Heat,  and  its  application  to  Air  and 
Steam  Engines.  8vo,  cloth  .................................  3  50 

MERRILL  (Col.  WM.  E  ,  U.  S.  A.)  Iron  Truss  Bridges  for 
Railroads.  T  he  method  of  calcu'ating  strains  in  Trusses, 
with  a  careful  comparison  of  the  most  prominent  Trusses,  in 
reference  to  economy  in  combination,  etc.,  etc.  Illustrated. 
4to,  cloth  ..................................................  5  oo 

tMICHAELIS  (Capt.  O.  E.,  U.  S.  A.)  The  Le  Boulenge 
Chronograph,  with  three  lithograph  folding  plates  of  illus- 
trations. 410,  cloth  ........................................  3  oo 


MICHIE  (Prof  P.  S.)  Elements  of  Wave  Motion  relating  to 
Sound  and  Light.  Text-Book  for  the  U.S.  Military  Acade- 
my. 8vo,  clot  h,  illustrated  .........................  .......  5  oo 


MINIFIE  (WM.)    Mechanical  Drawing.   A  Text-Book  of  Geo- 
metrical Drawing  for  the  use  of  Mechanics  and  Schools,  in 
which  the  Definitions  and  Rules  of  Geometry  are  familiarly 
explained  ;  the  Practical  Problems  are  arranged,  from  the 
most  simple  to  the  more  complex,  and  in  thejr  description 
technicalities  are  avoided  as  much  as  possible.    With  illus- 
trations  for   Drawing   Plans,    Sections,  and  Elevations  of 
Railways  and  Machinery;  an  Introduction  to  Isometrical 
Drawing,  and  an  Essayon  Linear  Perspective  and  Shadows. 
Illustrated  with  over  200  diagrams  engraved  on  steel.     Ninth 
edition.    With  an  Appendix  on  the  Theory  and  Application 
of  Colors.    8vo,  cloth  .....................................  4  oo 

"  It  is  the  best  work  on  Drawing  that  we  have  ever  seen,  and  is 
•especially  a  text-book  of  Geometrical  Drawing  for  the  use  of_  Me- 
chanics and  Schools.  No  young  Mechanic,  such  as  a  Machinist, 
Engineer,  Cabinet-maker,  Millwright,  or  Carpenter,  should  be  with- 
•out  it."  —  Scientific  American. 

-  Geometrical  Drawing.  Abridered  from  the  octavo  edi- 
tion, for  the  use  of  schools.  Illustrated  with  forty-eight 
steel  plates.  Fifth  edition.  I2mo,  cloth  .................  2  oo 


D.  VAN  NOSTRAND'S  PUBLICATIONS.  9 

MODERN  METEOROLOGY.  A  Series  of  Six  Lectures,  de- 
livered under  the  auspices  of  the  Meteorological  Society 
in  1878.  Illustrated.  I2mo, cloth ....  .  .§i  5* 

MORRIS  (E.)  Easy  Rules  for  the  Measurement  of  Earth- 
works, by  Means  of  the  Prismoidal  Formula.  78  illustra- 
tions. 8vo,  cloth i  5x1 

MOTT  (H.  A  , Jr.)  A  Practical  Treatise  on  Chemistry  (Qu-li- 
tative  and  Quantitative  Analysis),  Stoichiometry,  Blow-pipe 
Analysis,  Mineralogy,  Assaying',  Pharmaceutical  Prepara- 
tions, Human  Secretions,  Specific  Gravities,  Weights  an  I 
Measures,  etc.,  etc.,  etc.  New  edition,  1883.  630  pages. 
8vo,  cloth ,  400 

NAQUET  (A.)  Legal  Chemistry.  A  Guide  to  the  Detection  of 
Poisons,  Falsification  of  Writings,  Adulteration  of  Alimen- 
tary and  Pharmaceutical  Substances,  Analysis  of  Ashes, 
and  examination  of  Hair,  Coins.  Arms,  and  Stains,  as  ap- 
plied to  Chemical  Jurisprudence,  for  the  use  of  Chemists. 
Physicians,  Lawyers,  Pharmacists,  and  Experts.  Trans  at- 
ed,  with  additions,  including  a  list  of  books  and  Memoirs  on 
Toxicology,  etc.,  from  the  French.  By  T.  P.  Bittershall, 
Ph.D.,  with  a  prelace  by  C.  F.  Chandler,  Ph.D.,  M.D  , 
LL.D.  i2mo,  cloth 2  oo 

UOBLE !(W.  H.)     Useful  Tables.     Pocket  form,  cloth 50 

NUGENT  (E.)  Treatise  on  Optics ;  or,  Light  and  Sight,  then 
retically  and  practically  treated,  with  the  application  to 
Fine  Art  and  Industrial  Pursuits.  With  103  illustrations 
I2mo,  cloth i  «;o 

PEIRCE  (B.)    System  of  Analytic  Mechanics.    410,  cloth   ...  .10  oo 

PLANE  TABLE  <THE).  Its  Uses  in  Topographical  Survey- 
ing. From  the  Papers  of  the  U.  S.  Coast  Survey.  Illustrat- 
ed. 8vo,  cloth 200 

"  This  work  gives  a  description  of  the  Plane  Table  employed  at 

the  U.  S.  Coast  Survey  office,  and  the  manner  of  using  it." 

PLATTNER.  Manual  of  Qualitative  and  Quantitative  An- 
alysis with  the  Blow-Pipe.  From  the  last  German  editio", 
revised  and  enlarged.  By  Prof.  Th.  Richter,  of  the  Royal 
Saxon  Mining  Academy.  "  Translated  by  Prof  H.  B.  Corn- 
wall, assisted  by  John  H.Casweli.  Illustrated  with  87  wood- 
cuts and  one  lithographic  plate.  Fourth  edition,  revised, 
560  pages.  8vo,  cloth 5  co 

PLYMPTON(Prof.GEO.  W.)  The  Blow-Pipe.  A  Guide  to  its 
use  in  the  Determination  of  Salts  and  Minerals.  Compiled 

irom  various  sources,    izmo,  cloth i  50 

The  Aneroid  Barometer:    Its  Construction   and  Use. 
Compiled  from  several  sources.    i6mo,  boards,  illustrated,      50 
Morocco  ...  i  03 


10          D.  VAN  NOSTRAND'S  PUBLICATIONS. 

PLYMPTON  (Prof.  GEO.  W.)  The  Star-Finder,  or  Plani- 
!•  phere,  with  Movable  Horizon.  Printed  in  colors  on  fine 
card-board,  and  in  accordance  with  Proctor's  Star  Atlas.  .  .$i  oo 

POCKET  LOGARITHMS,  to  Four  Places  of  Decimals,  includ- 
ing Logarithms  of  Numbers,  and  Logarithmic  Sines  and 
Tangents  to  Single  Minutes.    To  which  is  added  a  Table  of 
Natural  Sines,  Tangents,  and  Co-Tangents.      i6mo,  boards,      y> 
Morocco  ...................................................  I  oo 

POOK  (S.  M.)  Method  of  Comparing  the  Lines  and  Draught- 
ing Vessels  propelled  by  Sail  or  Steam.  Including  a  chap- 
ter on  Laying-off  on  the  Mould-Loft  Floor,  i  vol.  8vo,  with 
illustrations,  cloth  ..........................................  5  OO- 

POPE  (F.  L.)  Modern  Practice  of  the  Electric  Telegraph.  A 
Hand-Book  for  Electricians  and  Operators.  Eleventh  edi- 
tion, revised  and  enlarged,  and  fully  illustrated.  8vo,  cloth.  2  oo> 

PRESCOTT  (Prof.  A.  B.)  Outlines  of  Proximate  Organic  An- 
alysis, for  the  Identification,  Separation,  and  Quantitative 
Determination  of  the  more  commonly  occurring  Organic 
Compounds.  I2mo,  cloth  ..................................  i  75, 

-  Chemical  Examination  of  Alcoholic  Liquors.    A  Manual 
of  the  Constituents  of  the  Distilled  Spirits  and  Fermented 
Liquors  of  Commerce,  and  their  Qualitative  and  Quantita- 
tive Determinations.     I2mo,  cloth  ..........................  i  5» 

-  First  Book  in  Qualitative  Chemistry.    Second  edition. 
I2mo,  cloth  ................................................  I  50- 

PYNCHON  (Prof.  T.  R.)  Introductjon  to  Chemical  Physics, 
designed  for  the  use  of  Academies,  Colleges,  and  High- 


Illustrated  with  numerous  engravings,  and  con- 
taining copious  experiments  with  directions  for  preparing 
them.  New  edition,  revised  and  enlarged,  and  illustrated 
by  269  illustrations  on  wood.  Crown  8vo,  cloth  .............  3  o& 

RAMMELSBERG  (C.  F.)  Guide  to  a  Course  of  Quantitative 
Chemical  Analysis,  especially  of  Minerals  and  Furnace  Pro- 
ducts. Illustrated  by  Examples.  Translated  by  J.  Towler, 
M.D.  8vo,  cloth  ..........................................  225 

RANDALL  (P.  M.)    Quartz  Operator's  Hand-Book.    New  edi- 

tion, revised  and  enlarged,  fully  illustrated.     I2mo,  cloth..  .  2  oo 

RANKINE  (W.  J.  M.)  Applied  Mechanics,  comprising-  Prin- 
ciples of  Statics,  Cinematics,  and  Dynamics,  and  Theory 
ot  Structures,  Mechanism,  and  Machines.  Crown  8vo, 
cloth.  Tenth  edition.  London  .......................  500 

-  -  A  Manual  of  the  Steam-Engine  and  other  Prime  Movers, 

with  numerous  tables  and  illustrations.      Crown  8vo,  cloth. 
Tenth  edition.    London,  1882  ...............................  5  oo- 

-  A  Selection  from  the  Miscellaneous  Scientific  Papers  of, 
with  Memoir  by  P.  G.  Tail,  and  edited  by  W.  J.  Millar,  C.E. 
8vo,  cloth.    London,  1880  ...................................  10  ot 


D.  VAN  NOSTRAND'S  PUBLICATIONS.  11 

RANKINE  (W.  J.  M.)  A  Manual  of  Machinery  and  Mill-work. 

Fourth  edition.    Crowm  8vo.     London,  1881     §500 

Civil    Engineering,    comprising    Engineering    Surveys. 

Earthwork,    Foundations,     Masonry,     Carpentry,     Metal- 
works,    Roads,    Railways,    Canals,    Rivers,    Water-works, 
Harbors,    etc.,    with     numerous    tables  and   illustrations. 
Fourteenth  edition,  revised  by  E.  F.  Bamber,  C.E.      8vo. 
London,  1883 6  50 

Useful   Rules  and  Tables  for  Architects,  Builders,  Car- 
penters,   Coachbuilders,    Engineers,     Founders,    Mechan- 
ics, Shipbuilders,  Surveyors,  Typefounders,  Wheelwrights, 

etc.     Sixth  edition.    Crown  8vo,  cloth.     London,  ifcts 4  co 

and  BAMBER  (E.  F.)    A  Mechanical  Text- Book ;  or, 

Introduction  to  the  Study  of  Mechanics  and  Engineering. 
8vo,  cl  >th.     London,   1875   '. 3  50 

RICE  !Prof.  J.  M.)  and  JOHNSON  (Prof.  W.  W.)  On  a  New 
Method  of  Obtaining  the  Differentials  of  Functions,  with 
especial  reference  to  the  Newtonian  Conception  of  Rates  or 
Velocities,  izmo,  paper  50 

ROGERS  (Prof.  H.  D.)  The  Geology  of  Pennsylvania.  A  Gov- 
ernment Survey,  with  a  General  View  of  the  Geology  of  the 
United  States,  Essays  on  the  Coal  Formation  and  its  Fos- 
sils, and  a  description  of  the  Coal  Fields  of  North  America 
and  Great  Britain.  Illustrated  with  Plates  and  Engravings 
in  the  text.  3  vols.  410,  cloth,  with  Portfolio  of  Maps 30  oo 

ROEBLING  (J.  A  )  Long  and  Short  Span  Railway  Bridges. 
Illustrated  with  large  copperplate  engravings  of  plans  and 
views.  Imperial  fofio,  cloth 25  oo 

JJOSE  (JOSHUA,  M.E.)  The  Pattern-Maker's  Assistant,  em- 
bracing Lathe  Work,  Branch  Work  Core  Work,Sweep  Work, 
and  Practical  Gear  Constructions,  the  Preparation  and  Use 
of  Tools,  together  with  a  large  collection  of  useful  and  val- 
uable Tables.  Third  edition.  Illustrated  with  250  engrav- 
ings. 8vo,  cloth  250 


SABINE  (ROBERT).  History  and  Progress  of  the  Electric  Tel- 
egraph, with  descriptions  of  some  of  the  apparatus.  Second 
edition,  with  additions,  i2mo,  cloth I  25 


SAELTZER  (ALEX  )    Treatise  on  Acoustics  in  connection  with 

Ventilation.     I2mo,  cloth I  oo 

.SCHUMANN  (F.)  A  Manual  of  Heating  and  Ventilation  in 
its  Practical  Application  for  the  use  of  Engineers  and  Archi- 
tects, embracing  a  series  ot  Tables  and  Formulae  for  dimen- 
sions of  heating,  flow  and  return  pipes  for  steam  and  hot- 
water  boilers,  flues,  etc.,  etc.  I2mo.  Illustrated.  Full 
roan I  50 

-~  Formulas  and  Tables  for  Architects  and  Engineers  in 
calculating  the  strains  and  capacity  of  structures  in  Iron 
and  WoocL  I2mo,  morocco,  tucks 2  50 


12          D.  VAN  NOSTRAND'S  PUBLICATIONS. 

SAWYER  (W.  E.)  Electric-Lighting  by  Incandescence,  and 
its  Application  to  Interior  Illumination.  A  Practical 
Treatise.  With  96  illustrations.  Third  edition.  8vo,  cloth.$2  50 

SCRIBNER  (J.  M.)  Engineers'  and  Mechanics'  Companion, 
comprising  United  States  Weights  and  Measures,  Mensura- 
tion of  Superfices  and  Solids,  Tables  of  Squares  and  Cubes, 
Square  and  Cube  Roots,  Circumference  and  Areas  of  Cir- 
cles, the  Mechanical  Powers,  Centres  of  Gravity,  Gravita- 
tion of  Bodies.  Pendulums,  Specific  Gravity  of  Bodies, 
Stiength,  Weight,  and  Crush  of  Materials,  Water-Wheels, 
Hydrostatics,  Hydraulics,  Statics,  Centres  of  Percussion 
and  Gyration,  Friction  Heat,  Tables  of  the  Weight  of 
Metals,  Scantling,  etc.,  Steam  and  the  Sieam-Engine. 
Nineteenth  edition,  revised,  i6mo,  full  morocco i  50 

Engineers',  Contractors',  and  Surveyors'  Pocket  Table- 

Book.  Comprising  Logarithms  of  Numbers,  Logarithmic 
Sines  and  Tangents,  Natural  Sines  and  Natural  Tangents, 
the  Traverse  Table,  and  a  full  and  complete  set  of  Excava- 
tion and  Embankment  Tables,  together  with  numerous 
other  valuable  tables  for  Engineers,  etc.  Eleventh  edition, 
revised,  i6mo,  full  morocco  I  50 

SHELLEN  (Dr.  H.)  Dynamo-Electric  Machines.  Translated, 
with  much  new  matter  on  American  practice,  and  many  il- 
lustrations which  now  appear  for  the  first  time  in  print, 
fcvo,  cloth,  New  York (In  press) 

SHOCK  (Chief-Eng.  W.  H.)  Steam-Boilers :  their  Design, 
Construction,  and  Management.  450  pages  text.  Illustrated 
with  150  wood-cuts  and  36  full-page  plates  (several  double). 
Quarto.  Illustrated.  Half  morocco 1500 

SHUNK  (W.  F.)  The  Field  Engineer.  A  handy  book  of  prac- 
tice in  the  Survey,  Location,  and  Track-work  of  Railroads, 
containing  a  large  collection  of  Rules  and  Tables,  original 
and  selected,  applicable  to  both  the  Standard  and  Narrow 
Gauge,  and  prepared  with  special  reference  to  the  wants  of 
the  young  Engineer.  Third  edition.  i2mo,  morocco, 
tucks 250 

SHIELDS  (J.  E.)  Notes  on  Engineering  Construction.  Em- 
bracing Discussions  of  the  Principles  involved,  and  Descrip- 
tions of  the  Material  employed  in  Tunnelling,  Bridging, 
Canal  and  Road  Building,  etc.,  etc.  umo,  cloth I  g» 

SHREVE  (S.  H  )  A  Treatise  on  the  Strength  of  Bridges  and 
Roofs.  Comprising  the  determination  of  Algebraic  formu- 
las for  strains  in  Horizontal,  Inclined  or  Rafter,  Trinngular, 
Howstring,  Lenticular,  and  other  Trusses,  from  fixed  and 
moving  loads,  with  practical  applications  and  examples,  for 
the  use  of  Students  and  Engineers.  87  wood-cut  illustra- 
tions. Third  edition.  8 vo,  cloth 350 


UNIVERSITY    OF    CALIFORNIA 
LIBRARY 


Due  two  weeks  after  date. 

-•tr.  f. 


30m-7,'12 


THE  UNIVERSITY  OF  CALIFORNIA  LIBRARY 


